Trouble with dynamic arrays and string occurence (C++) - c++

I am working on a lab for my C++ class. I have a very basic working version of my lab running, however it is not quite how it is supposed to be.
The assignment:
Write a program that reads in a text file one word at a time. Store a word into a dynamically created array when it is first encountered. Create a parallel integer array to hold a count of the number of times that each particular word appears in the text file. If the word appears in the text file multiple times, do not add it into your dynamic array, but make sure to increment the corresponding word frequency counter in the parallel integer array. Remove any trailing punctuation from all words before doing any comparisons.
Create and use the following text file containing a quote from Bill Cosby to test your program.
I don't know the key to success, but the key to failure is trying to please everybody.
At the end of your program, generate a report that prints the contents of your two arrays in a format similar to the following:
Word Frequency Analysis
Word Frequency
I 1
don't 1
know 1
the 2
key 2
...
I can figure out if a word repeats more than once in the array, but I cannot figure out how to not add/remove that repeated word to/from the array. For instance, the word "to" appears three times, but it should only appear in the output one time (meaning it is in one spot in the array).
My code:
using namespace std;
int main()
{
ifstream file;
file.open("Quote.txt");
if (!file)
{
cout << "Error: Failed to open the file.";
}
else
{
string stringContents;
int stringSize = 0;
// find the number of words in the file
while (file >> stringContents)
{
stringSize++;
}
// close and open the file to start from the beginning of the file
file.close();
file.open("Quote.txt");
// create dynamic string arrays to hold the contents of the file
// these will be used to compare with each other the frequency
// of the words in the file
string *mainContents = new string[stringSize];
string *compareContents = new string[stringSize];
// holds the frequency of each word found in the file
int frequency[stringSize];
// initialize frequency array
for (int i = 0; i < stringSize; i++)
{
frequency[i] = 0;
}
stringContents = "";
cout << "Word\t\tFrequency\n";
for (int i = 0; i < stringSize; i++)
{
// if at the beginning of the iteration
// don't check for the reoccurence of the same string in the array
if (i == 0)
{
file >> stringContents;
// convert the current word to a c-string
// so we can remove any trailing punctuation
int wordLength = stringContents.length() + 1;
char *word = new char[wordLength];
strcpy(word, stringContents.c_str());
// set this to no value so that if the word has punctuation
// needed to remove, we can modify this string
stringContents = "";
// remove punctuation except for apostrophes
for (int j = 0; j < wordLength; j++)
{
if (ispunct(word[j]) && word[j] != '\'')
{
word[j] = '\0';
}
stringContents += word[j];
}
mainContents[i] = stringContents;
compareContents[i] = stringContents;
frequency[i] += 1;
}
else
{
file >> stringContents;
int wordLength = stringContents.length() + 1;
char *word = new char[wordLength];
strcpy(word, stringContents.c_str());
// set this to no value so that if the word has punctuation
// needed to remove, we can modify this string
stringContents = "";
for (int j = 0; j < wordLength; j++)
{
if (ispunct(word[j]) && word[j] != '\'')
{
word[j] = '\0';
}
stringContents += word[j];
}
// stringContents = "dont";
//mainContents[i] = stringContents;
compareContents[i] = stringContents;
// search for reoccurence of the word in the array
// if the array already contains the word
// don't add the word to our main array
// this is where I am having difficulty
for (int j = 0; j < stringSize; j++)
{
if (compareContents[i].compare(compareContents[j]) == 0)
{
frequency[i] += 1;
}
else
{
mainContents[i] = stringContents;
}
}
}
cout << mainContents[i] << "\t\t" << frequency[i];
cout << "\n";
}
}
file.close();
return 0;
}
I apologize if the code is difficult to understand/follow through. Any feedback is appreciated :]

If you use stl, the entire problem can be solved easily, with less coding.
#include <iostream>
#include <fstream>
#include <string>
#include <unordered_map>
#include <algorithm>
using namespace std;
int main()
{
ifstream file("Quote.txt");
string aword;
unordered_map<string,int> wordFreq;
if (!file.good()) {
cout << "Error: Failed to open the file.";
return 1;
}
else {
while( file >> aword ) {
aword.erase(remove_if(aword.begin (), aword.end (), ::ispunct), aword.end ()); //Remove Punctuations from string
unordered_map<string,int>::iterator got = wordFreq.find(aword);
if ( got == wordFreq.end() )
wordFreq.insert(std::make_pair<string,int>(aword.c_str(),1)); //insert the unique strings with default freq 1
else
got->second++; //found - increment freq
}
}
file.close();
cout << "\tWord Frequency Analyser\n"<<endl;
cout << " Frequency\t Unique Words"<<endl;
unordered_map<string,int>::iterator it;
for ( it = wordFreq.begin(); it != wordFreq.end(); ++it )
cout << "\t" << it->second << "\t\t" << it->first << endl;
return 0;
}

The algorithm that you use is very complex for such a simple task. Here is what you sahll do:
Ok, first reading pass for determining the maximum size of the
array
Then second reading pass, look directly at what to do: if string is already in the table just increment its frequency, otherwise add it to the table.
Output the table
The else block of your code would then look like:
string stringContents;
int stringSize = 0;
// find the number of words in the file
while (file >> stringContents)
stringSize++;
// close and open the file to start from the beginning of the file
file.close();
file.open("Quote.txt");
string *mainContents = new string[stringSize]; // dynamic array for strings found
int *frequency = new int[stringSize]; // dynamic array for frequency
int uniqueFound = 0; // no unique string found
for (int i = 0; i < stringSize && (file >> stringContents); i++)
{
//remove trailing punctuations
while (stringContents.size() && ispunct(stringContents.back()))
stringContents.pop_back();
// process string found
bool found = false;
for (int j = 0; j < uniqueFound; j++)
if (mainContents[j] == stringContents) { // if string already exist
frequency[j] ++; // increment frequency
found = true;
}
if (!found) { // if string not found, add it !
mainContents[uniqueFound] = stringContents;
frequency[uniqueFound++] = 1; // and increment number of found
}
}
// display results
cout << "Word\t\tFrequency\n";
for (int i=0; i<uniqueFound; i++)
cout << mainContents[i] << "\t\t" << frequency[i] <<endl;
}
Ok, it's an assignment. So you have to use arrays. Later you could sumamrize this code into:
string stringContents;
map<string, int> frequency;
while (file >> stringContents) {
while (stringContents.size() && ispunct(stringContents.back()))
stringContents.pop_back();
frequency[stringContents]++;
}
cout << "Word\t\tFrequency\n";
for (auto w:frequency)
cout << w.first << "\t\t" << w.second << endl;
and even have the words sorted alphabetically.

Depending on whether or not your assignment requires that you use an 'array', per se, you could consider using a std::vector or even a System::Collections::Generic::List for C++/CLI.
Using vectors, your code might look something like this:
#include <vector>
#include <string>
#include <fstream>
#include <iostream>
using namespace std;
int wordIndex(string); //Protoype a function to check if the vector contains the word
void processWord(string); //Prototype a function to handle each word found
vector<string> wordList; //The dynamic word list
vector<int> wordCount; //The dynamic word count
void main() {
ifstream file("Quote.txt");
if (!file) {
cout << "Error: Failed to read file" << endl;
} else {
//Read each word into the 'word' variable
string word;
while (!file.eof()) {
file >> word;
//Algorithm to remove punctuation here
processWord(word);
}
}
//Write the output to the console
for (int i = 0, j = wordList.size(); i < j; i++) {
cout << wordList[i] << ": " << wordCount[i] << endl;
}
system("pause");
return;
}
void processWord(string word) {
int index = wordIndex(word); //Get the index of the word in the vector - if the word isn't in the vector yet, the function returns -1.
//This serves a double purpose: Check if the word exsists in the vector, and if it does, what it's index is.
if (index > -1) {
wordCount[index]++; //If the word exists, increment it's word count in the parallel vector.
} else {
wordList.push_back(word); //If not, add a new entry
wordCount.push_back(1); //in both vectors.
}
}
int wordIndex(string word) {
//Iterate through the word list vector
for (int i = 0, j = wordList.size(); i < j; i++) {
if (wordList[i] == word) {
return i; //The word has been found. return it's index.
}
}
return -1; //The word is not in the vector. Return -1 to tell the program that the word hasn't been added yet.
}
I've tried to annotate any new code/concepts with comments to make it easy to understand, so hopefully you can find it useful.
As a side note, you may notice that I've moved a lot of the repetative code out of the main function and into other functions. This allows for more efficient and readable coding because you can divide each problem into easily manageable, smaller problems.
Hope this can be of some use.

Related

Converting this program from 1 function to a modular, multi-function program?

I am very new to C++ and have a program which I included below.
The program I am working on reads text from an input file and counts the number of words and number of occurrences of each letter in the text and then prints the results. My program is working fine but the problem is all code is written in the main function and I need to break it up into a couple more functions to make the program modular, but I am unsure of how to go about doing this.
I am sure this is pretty simple but I'm not sure where to start. I was thinking of implementing two void functions, one for reading / interpreting what is read from the data file and another that displays the results; and then call them both in the main function, but I'm not sure what to take as arguments for those functions.
int main()
{
// Declaring variables
char c; // char that will store letters of alphabet found in the data file
int count[26] = {0}; // array that will store the # of occurences of each letter
int words = 1; // int that will store the # of words
string s; // declaring string found in data file
// Opening input file stream
ifstream in;
in.open("word_data.txt");
// Reading text from the data file
getline(in, s);
//cout << s << endl;
// If input file fails to open, displays an error message
if (in.fail())
{
cout << "Input file did not open correctly" << endl;
}
// For loop for interpreting what is read from the data file
for (int i = 0; i < s.length(); i++) {
// Increment word count if new line or space is found
if (s[i] == ' ' || s[i] == '\n')
words++;
//If upper case letter is found, convert to lower case.
if (s[i] >= 'A' && s[i] <= 'Z')
s[i] = (tolower(s[i]));
//If the letters are found, increment the counter for each letter.
if (s[i] >= 'a' && s[i] <= 'z')
count[s[i] - 97]++;
}
// Display the words count
cout << words << " words" << endl;
// Display the count of each letter
for (int i = 0; i < 26; i++) {
if (count[i] != 0) {
c = i + 97;
cout << count[i] << " " << c << endl;
}
}
// Always close opened files
in.close();
return 0;
}
I would rewrite it like:
class FileReader {
public:
FileReader() {
// Any init logic goes here...
}
~FileReader() {
// Always close opened files.
in.close();
}
void open(std::string &filePath) {
in.open(filePath);
}
std::string readLine() {
std::string s;
getline(in, s);
return s;
}
bool hasErrors() const { // remove const if you get compile-error here.
return in.fail();
}
private:
ifstream in;
};
class LetterCounter {
public:
void process(std::string &s) {
// For loop for interpreting what is read from the data file
for (int i = 0; i < s.length(); i++) {
// Increment word count if new line or space is found
if (s[i] == ' ' || s[i] == '\n')
words++;
//If upper case letter is found, convert to lower case.
if (s[i] >= 'A' && s[i] <= 'Z')
s[i] = (tolower(s[i]));
//If the letters are found, increment the counter for each letter.
if (s[i] >= 'a' && s[i] <= 'z')
count[s[i] - 97]++;
}
}
void logResult() {
char c; // char that will store letters of alphabet found in the data file.
// Display the words count
cout << words << " words" << endl;
// Display the count of each letter
for (int i = 0; i < 26; i++) {
if (count[i] != 0) {
c = i + 97;
cout << count[i] << " " << c << endl;
}
}
}
private:
int count[26] = {0}; // array that will store the # of occurences of each letter
int words = 1; // int that will store the # of words
};
int main()
{
// Opening input file stream.
FileReader reader;
reader.open("word_data.txt");
// Reading text from the data file.
std::string s = reader.readLine();
// If input file fails to open, displays an error message
if (reader.hasErrors()) {
cout << "Input file did not open correctly" << endl;
return -1;
}
LetterCounter counter;
counter.process(s);
// Display word and letter count.
counter.logResult();
return 0;
}
Note that I did write without testing (excuse any mistake),
but this should give you a general idea how it should be.

Palindromes in C++

I'm trying to make a program that uses stacks (w pop, push, etc.) to read in a text file with lots of sentences that are taken one at a time and outputs whether each line is a palindrome or not (words that are spelled the same forwards and backwards). I believe its very close to being a completed program, but it only returns false even when the string is a palindrome. I want it to return true when the string is in fact a palindrome.
EDIT: Tried a new method with three stacks instead. Still getting a false return from bool tf every time.
int main() {
Stack s(100); // Initialize two different stacks
Stack q(100);
Stack temp(100);
string line; // String to hold each individual line of the file
char letter;
char x; // For comparisons
char y;
// open the file
ifstream input;
input.open(READFILE);
// Check that it is open/readable
if (input.fail()) {
cout << endl << "Sorry, file not available, exiting program. Press enter";
cout << endl;
cin.get(); // Grab the enter
return 0;
}
while (getline(input, line)) { // Read the file line-by-line into "line"
cout << "The line: " << line << endl;
int length = line.length(); // Sets length equal to string length
for (int i =0; i<length; i++){ // Capitalizes string
line[i] = toupper(line[i]);
}
for (int i = 0; i < length; i++) { // Loop through for every letter in the line
if (line[i] == ' ' ) {
line.erase(i,1); // Takes spaces out of the line
length--;
}
if (ispunct(line[i])){
length--;
}
if (!ispunct(line[i])){ // Removes punctuation
letter = line[i]; // Push each letter onto the stack
s.push(letter);
}
}
for (int i = 0; i < length; i++) { // Popping half the letters off of the s stack
s.pop(letter); // and pushing them onto the q stack
q.push(letter);
temp.push(letter);
}
for (int i = 0; i < length; i++) {
temp.pop(letter);
s.push(letter);
}
bool tf = true; // Pop off the top of each stack and compare
while (!s.empty()) { // them to check for a palindrome
s.pop(x);
q.pop(y);
if (x == y);
else tf = false;
}
if (tf){
cout << "is a palindrome!" << endl;
}
if (!tf) {
cout << "is NOT a palindrome" << endl;
}
}
}
for (int i = 0; i < length/2; i++) // Popping half the letters off
//of the s stack
q.push(letter); // and pushing them onto the q
//stack
}
Here you're pushing the same letter over and over again.
Even if you rewrite as the comment states it will be wrong.
if you pop half of ABBA you have BA and AB and compare B=A
you need to rethink your strategy. Maybe push half of the string to s then loop backwards from length and push to q
Like someone else mentioned, even after fixing the for loop with the "q" stack, the general strategy is not correct. In fact you don't need two stacks. (or even one stack, but you can use a stack if desired.)
You do have the right idea in comparing the back half of the letters with the front half. In general, to find a palindrome you just need to see if the string is equal to the reversed string or that the first half is equal to the back half.
You can use a stack to store the string in reverse. All you need is the stack and the string. However, there is the extra problem here in that the lines of strings contain spaces and punctuation that you want to ignore. Using the erase() method reduces the length of the string as you go, so you need a temporary variable to rebuild the formatted string at the same time as the stack. EDIT: I saw your update to accounting for the reduced length; that's great -- it can save even the use of a temp variable to hold the formatted string so that the variable string line is all that is needed.
Here is another version of your while loop that uses one stack and a temp string variable. It uses half the formatted string to compare against the top of the stack (which represents the "back" of the string).
string cleanString;
//cout << "test3";
while (getline(input, line)) { // Read the file line-
//by-line into "line"
cout << "The line read was: " << line << endl;
int length = line.length(); // Sets length equal to
//string length
for (int i =0; i<length; i++) // Capitalizes string
line[i] = toupper(line[i]);
for (int i = 0; i < length; i++) // Loop through for //every letter in the line
if ( !(line[i] == ' ' || ispunct(line[i]))) { // Ignore space & punctuation
letter = line[i]; // Push each letter onto
s.push(letter); //the stack
cleanString.push_back(letter); //and to the "cleaned" string to compare with later
//cout << cleanString << endl; //test
}
length = cleanString.length();
bool tf = true;
for (int i = 0; i < length/2; i++) { // Pop off the top of stack
s.pop(x); // to compare with front of string
if ( cleanString[i] != x ) { //not a palindrome
tf = false;
break;
}
}
if (tf){
cout << "is a palindrome!" << endl;
}
if (!tf) {
cout << "is NOT a palindrome" << endl;
}
}
But it's simpler to skip the use of the stack altogether and instead just use the temp "cleaned" string, checking for a palindrome in a for loop with two counters: one for the the front and one for the back.
So after the capitalization:
// Instead of a stack, just build a string of chars to check for a palindrome
for (int i = 0; i < length; i++)
if ( !(line[i] == ' ' || ispunct(line[i]))) {
letter = line[i]; // Push each letter onto
cleanString.push_back(letter); // a temp string
}
length = cleanString.length(); //use length of formatted string
bool tf = true;
int front = 0; // first char of string
int back = length-1; // last char of string
for (; i < length/2; front++, back--)
if ( cleanString[front] != cleanString[back] ) { //not a palindrome
tf = false;
break;
}
Another option is to use the inbuilt reverse() function in the <algorithm> header file after building the temp string:
#include <algorithm> // reverse()
string cleanString;
string reversedCleanString;
//...
// Instead of a stack, just build a string of chars to check for a palindrome
for (int i = 0; i < length; i++)
if ( !(line[i] == ' ' || ispunct(line[i])))
cleanString.push_back(line[i]);
reversedCleanString = cleanString; // store copy of string to reverse
reverse(reversedCleanString.begin(), reversedCleanString.end() ); // reverse
bool tf = true;
if ( cleanString != reversedCleanString)
tf = false;
// ...
As moooeeep mentioned the comments, using std::string's reverse iterators simplifies this even further after the capitalization:
string cleanString;
//...
// Format line to test if palindrome
for (int i = 0; i < length; i++)
if ( !(line[i] == ' ' || ispunct(line[i])))
cleanString.push_back( line[i] );
bool tf = true;
if ( cleanString != string(cleanString.rbegin(), cleanString.rend() )
tf = false;
// ...
Also, like moooeeeep mentioned, encapsulating the different parts of the while loop into their own separate functions is a good idea to make not just debugging easier but also understanding the logical flow of the problem more intuitively.
For example the while loop could look like this:
while (getline(input, line)) { // Read the file line-by-line into "line"
//echo input
cout << "The line read was: " << line << endl;
// validate/format the line
extractChars( line ); //remove space/punctuation
capitalizeString( line ); // capitalize chars for uniformity
//check if formatted line is a palindrome and output result
if ( is_palindrome( line ) )
cout << "Line IS a palindrome << endl;
else
cout << "Line IS NOT a palindrome << endl;
}

Reading words from an input file and counting unique words

Hey everyone I've been having some trouble with this assignment. I need to:
Read each word of the input file. For each word:
If the word already exists in your word inventory, then simply add 1 to the count. Do not add a duplicate word to your inventory.
If the word does not exist in your word inventory, add it and set the count to 1.
After reading all of the input file, close the input file.
Sort the word inventory by ASCII word order
Display the word inventory, i.e. list the words and their counts. The output should be sorted in ASCII word order.
My allowed library's are iostream, iomanip, string, cstring, cerrno, limits, sstream, fstream, cmath.
So far, I've been having difficulties with counting the words! My code counts the characters, not the words. My code so far is as follows:
#include "appl.h"
using namespace std;
/*
Class definition file for Appl
*/
string getFileName(ios_base::open_mode parm);
struct wordBlock {
string word;
int count;
};
// Constructor
Appl::Appl()
{
// id string is required for all CS 162 submissions. *** DO NOT CHANGE ***
_cs162_id_ = new string(__FILE__ + string(" compiled ")
+ __DATE__ + string(" ") + __TIME__
+ string(" using g++ ") + to_string(__GNUC__)
+ string(".") + to_string(__GNUC_MINOR__) + string(".")
+ to_string(__GNUC_PATCHLEVEL__));
}
// Destructor
Appl::~Appl()
{
delete _cs162_id_;
}
string inputFileName(ios_base::open_mode parm){
fstream iFile;
string inFileName = "";
int count = 1;
if(parm == ios::in){
while(count != 0){
cout << "Enter an input file name that exists: ";
getline(cin,inFileName);
iFile.open(inFileName.c_str() , ios::in);
if(iFile.good() != true){
cout << "?Invalid file name : file does not exist" <<
count++;
iFile.clear();
}else{
count = 0;
iFile.close();
return inFileName;
}
}
}
}
// Main Routine
int Appl::main(int argc, char ** argv)
{
fstream inFile;
string inFileNames;
inFileNames = inputFileName(ios::in);
inFile.open(inFileNames.c_str(), ios::in);
wordBlock inventory[1000];
if(inFile.is_open()){
for(auto idx = 0; idx < 1000; idx ++){
inventory[idx].word = idx;
inventory[idx].count = 0;
}
while(inFile.peek() != EOF) {
inventory[inFile.get()].count++;
}
for(auto idx = 0; idx < 1000; idx++){
inventory[idx].word = idx;
inventory[idx].count = 0;
}
while(inFile.peek() != EOF) {
inventory[inFile.get()].count++;
}
for(auto idx = 0; idx < 1000; idx++){
if(inventory[idx].count == 0) continue;
cout << "Word " << inventory[idx].word << " occurs " << inventory[idx].count << " times" << endl;
}
inFile.clear();
inFile.close();
}
return 0;
}
you might wanna use set from stl
declare a set of string type
set <string> mySet;
bool myfunc(string word){
pair<set<string>::iterator,bool>unique;
/* use #include<utility>
when a set insertion returns a pair of values, the second one is boolean type. and as set's element is always sorted and unique, it makes our life easy*/
unique = mySet.insert(word);
return unique.second;
}
In pseudo code you need to do the following to get the counts:
Create a counter to keep track of the number of words in your inventory, must be 0 at the start (lets call it wordCount).
Read a single word from the file.
run through all of your added words and see if the word is in the list
from 0 to wordCount
Compare the newWord with the word at inventory[index]
If they match, increment the count at inventory[index] and stop loop
If they do not match, go to next one.
If at end of wordCount and did not find it, set inventory[wordCount]to the word with 0 count and increment wordCount.
Since you have 0-based indexing, the word in your inventory at the current count should be empty, thus add it as the new word and increment the count.
repeat until all words are read.
To sort the words, read up on a sorting algorithm, something like bubble sort should be easy enough to implement:
the operator< can be used: if(str1 < str2) {}

Store a word into a dynamically created array when first encountered

Here is the assignment:
Write a program that reads in a text file one word at a time. Store a word into a dynamically created array when it is first encountered. Create a paralle integer array to hold a count of the number of times that each particular word appears in the text file. If the word appears in the text file multiple times, do not add it into your dynamic array, but make sure to increment the corresponding word frequency counter in the parallel integer array. Remove any trailing punctuation from all words before doing any comparisons.
Create and use the following text file containing a quote from Bill Cosby to test your program.
I don't know the key to success, but the key to failure is trying to please everybody.
At the end of your program, generate a report that prints the contents of your two arrays in a format similar to the following:
Word Frequency Analysis
I 1
don't 1
know 1
the 2
key 2
...
Here is my code:
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int readInFile (string tempArray [], string file, int arraySize);
int main()
{
ifstream inputFile;
string *readInArray = 0,
*compareArray = 0,
filename,
word;
int wordCount = 0;
int encountered = 0;
int j = 0,
*wordFrequency = 0;
cout << "Enter the filename you wish to read in: ";
getline(cin, filename);
inputFile.open(filename.c_str());
if (inputFile)
{
while (inputFile >> word)
{
wordCount++;
}
inputFile.close();
readInArray = new string[wordCount];
readInFile(readInArray, filename, wordCount);
}
else
{
cout << "Could not open file, ending program";
return 0;
}
compareArray = new string[wordCount];
wordFrequency = new int[wordCount];
for (int count = 0; count < wordCount; count++)
wordFrequency[count] = 0;
for(int i = 0; i < wordCount; ++i)
{
j = 0;
encountered = 0;
do
{
if (readInArray[i] == compareArray[j])
encountered = 1;
++j;
} while (j < wordCount);
if (encountered == 0)
{
compareArray[i]=readInArray[i];
wordFrequency[i] += 1;
}
}
for(int k=0; k < wordCount; ++k)
{
cout << "\n" << compareArray[k] << " ";
}
for(int l=0; l < wordCount; ++l)
{
cout << "\n" << wordFrequency[l] << " ";
}
return 0;
}
int readInFile (string tempArray [], string file, int arraySize)
{
ifstream inputFile;
inputFile.open(file.c_str());
if (inputFile)
{
cout << "\nHere is the text file:\n\n";
for(int i=0; i < arraySize; ++i)
{
inputFile >> tempArray[i];
cout << tempArray[i] << " ";
}
inputFile.close();
}
}
Here is my question:
How do you store a word into a dynamically created array when it is first encountered? As you can see from my code made a string array with some of the elements empty. I believe it is suppose to be done using pointers.
Also how do I get rid of the punctuation in the string array? Should it be converted to a c-string first? But then how would I compare the words without converting back to a string array?
Here is a link to a java program that does something similar:
http://math.hws.edu/eck/cs124/javanotes3/c10/ex-10-1-answer.html
Thank you for any help you can offer!!
As to the first part of your question, you are not using a dynamically created array. You are using a regular array. C++ provides implementations of dymnamic arrays, like the vector class http://www.cplusplus.com/reference/vector/vector/
As to the second part of your question, I see no reason to convert it to a c string. The string class in c++ provides functionality for removing and searching for characters. http://www.cplusplus.com/reference/string/string/
The string::erase function can be used to erase punctuation characters found with string::find.
Note: There are other ways of doing this assignment that may be easier (like having an array of structs containing a string and an int, or using a map) but that may defeat the purpose of the assignment.

Anagram generator for C++ (not using STL)

I am trying to create an anagram solver just using a very basic, procedural approach. I am finding out that I probably should have done this using classes, but now it is too late and my assignment is about due. Any suggestions on how to figure this out would be great!
Basically, this is what the algorithm should do:
Get all words in the dictionary; store them in a container
Get a word from the user; quit if appropriate
Get all permutations of the word that the user entered
Strip the word the user entered from the permutations
Strip all words in the permutation collection that aren't also in the dictionary I collected in part 1
Now for the last step, I must make sure that I don't display duplicate anagrams (i.e. anagrams which contain the same letter, such as "loop"). I cannot seem to get this check to work, which is noted below with under the TODO comment block.
Any suggestions would be awesome!!
#include <iostream>
#include <fstream>
#include <string>
//
// Change size below to accomodate more anagrams and dictionary words
//
#define MAX_ANGM_SIZE 4096
#define MAX_WORD_SIZE 1048576
using namespace std;
//
// Determines whether anagram is valid or not; will not display word
// which user entered or words not contained in dictionary
//
bool isValidAnagram(string word, string userWord,
string dictionary[], unsigned int listIdx)
{
for(unsigned int idx = 0; idx < listIdx; ++idx)
{
if(word == userWord)
return false;
else if (word == dictionary[idx])
return true;
}
return false;
}
//
// Determines whether user's word is contained in the dictionary
// or not
//
bool isValidWord(string word, string dictionary[],
unsigned int listIdx)
{
for(unsigned int idx = 0; idx < listIdx; ++idx)
{
if(word == dictionary[idx])
return true;
}
return false;
}
//
// TODO:This function should test for duplicate anagrams and return
// true if duplicates are found.
//
bool isRepeated(string anagrams[], unsigned int anaIdx)
{
for(unsigned int idx = anaIdx; idx != 0; --idx)
{
if(anagrams[idx] == anagrams[anaIdx])
return true;
else
return false;
}
return false;
}
//
// Only display elements in array which aren't blank and don't
// display duplicate anagrams; notify user if no anagrams
// were found.
//
void displayAnagrams(string anagrams[], unsigned int next)
{
int flag = 0;
for (unsigned int idx = 0; idx < next; ++idx)
{
if((anagrams[idx] != "") || (!(isRepeated(anagrams, idx))))
{
if(idx == 1)
cout << " Anagrams: ";
if(idx > 0)
flag = 1;
cout << anagrams[idx] << " ";
}
else
continue;
}
if(flag == 0)
cout << " no anagrams found" << endl;
}
static void swap(char &c1, char &c2)
{
char temp = c1;
c1 = c2;
c2 = temp;
}
//
// Pass in word to be altered, the userWord for comparison, the array to store
// anagrams, the dictionary for comparison, the count for the number of anagrams
// and the count for number of dictionary words
//
static void permute(string word, string userWord, int k, string anagrams[],
string dictionary[], unsigned int &next, unsigned int listIdx)
{
if(k == word.length()-1)
{
if(isValidAnagram(word, userWord, dictionary, listIdx))
anagrams[next] = word;
++next;
}
else
{
for(int idx = k; idx < word.length(); ++idx)
{
swap(word[k], word[idx]);
permute(word, userWord, k+1, anagrams, dictionary, next, listIdx);
}
}
}
//
// Create container to store anagrams, validate user's word in dictionary, get all
// of the anagrams, then display all valid anagrams
//
void getAnagrams(string word, string dictionary[], unsigned int listIdx)
{
string anagrams[MAX_ANGM_SIZE];
unsigned int next = 0;
if(isValidWord(word, dictionary, listIdx))
{
permute(word, word, 0, anagrams, dictionary, next, listIdx);
}
else
{
cerr << " \"" << word << "\"" << " is not a valid word" << endl;
return;
}
displayAnagrams(anagrams, next);
}
//
// Read in dictionary file, store contents of file in a list, prompt
// the user to type in words to generate anagrams
//
int main()
{
string file;
string word;
string quit = "quit";
string dictionary[MAX_WORD_SIZE];
unsigned int idx = 0;
cout << "Enter a dictionary file: ";
cin >> file;
cout << "Reading file \"" << file << "\"" << endl;
cout << endl;
ifstream inFile(file.c_str());
if(!(inFile.is_open()))
{
cerr << "Can't open file \"" << file << "\""
<< endl;
exit(EXIT_FAILURE);
}
while(!inFile.eof())
{
inFile >> dictionary[idx];
++idx;
}
inFile.close();
while(true)
{
cout << "Enter a word: ";
cin >> word;
if(word == quit) break;
getAnagrams(word, dictionary, idx);
cout << endl;
}
return 0;
}
You may want to rethink your step (3). If the user enters a 12-letter word you have 479,001,600 permutations of it which will probably be impractical to assemble all at once (and if that's not, then a 16-letter word will be...).
Instead, try thinking about how you could store the words and look up potential anagrams in a way that doesn't require you to do that.
Edit: I get that ability to solve largeish words may not be your biggest concern at this point, but it might actually make your fourth and fifth steps easier if you do them by assembling the set of valid words rather than starting with all possibilities and removing all the ones that don't match. 'Removing' an item from an array is a bit awkward since you have to shuffle all the following items up to fill in the gap (this is exactly the kind of thing that STL manages for you).
Better algorithm : don't store your word, but store a tupple containing (your word, sorted letters). Moreover, you sort that big storage by the second key (hint, you could use a sqlite database to do the work for you and use an index (can't be unique!))
E.g. to store
"Florent", "Abraham","Zoe"
you would store in memory
("aaabhmr", "abraham"),("eflnort","florent"),("eoz","zoe")
When you got your word from your user, you just use same "sorting letter inside word" algorithm.
Then you look for that pattern in your storage, and you find all anagrams very quickly (log(size of dictionary)) as it's sorted. Of course, original words are the second elements of your tuple.
You can do that using classes, standard structures, a database, up to you to choose the easiest implementation (and the one fitting your requirements)