My code has an if else statement which verifies whether an input is a string full of alpha characters.
The code works but the cout << original << "\n"; part prints out the result 5 times. I think the root of the issue lies within the for (std::string::iterator it=original.begin(); it!=original.end(); ++it) line, specifically the ++it bit.
Below is the code:
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <string>
#include <locale>
#include <iostream>
using namespace std;
int main(int nNumberofArgs, char* pszArgs[])
{
std::locale loc;
std::string original;
std::cout << "Welcome to the English to Pig Latin translator!\n";
std::cout << "Type a word you wish to translate:\n";
std::getline(std::cin, original);
std::cout << "Your word: " << original << "\n";
for (std::string::iterator it=original.begin(); it!=original.end(); ++it)
{
if (original.length() > 0 && std::isalpha(*it,loc) )
{
std::string word;
std::transform(original.begin(), original.end(), original.begin(), ::tolower);
cout << original << "\n";
}
else
{
std::cout << "Please enter a valid word." << std::endl;
}
}
system("PAUSE");
return 0;
}
This link is a screenshot of my CLI output:
http://gyazo.com/5b9cea385794fecc39ed578b539a84c3
It's printing five times because "hello" is five characters long. Your for loop is running once for each character in the string.
Your code is not correct. It checks for each character rather than the entire string.
Change it to:
bool alphaString = true;
for (std::string::iterator it=original.begin(); it!=original.end(); ++it)
{
if (! std::isalpha(*it,loc) )
{
std::cout << "Please enter a valid word." << std::endl;
alphaString = false;
break;
}
}
if ( alphaString ) {
std::transform(original.begin(), original.end(), original.begin(), ::tolower);
cout << original << "\n";
}
Related
I need to convert letters into a dictionary of characters.
Here's an example:
letter
l: 1
e: 2
t: 2
r: 1
I did some research and found this helpful answer, but that was using getline() and separating words by spaces. Since I am trying to split by character I don't think I can use getline() since '' isn't a valid split character. I could convert to a char* array but I wasn't sure where that would get me.
This is fairly easy in other languages so I thought it wouldn't be too bad in C++. I was hoping there would be something like a my_map[key]++ or something. In Go I would write this as
// Word map of string: int values
var wordMap = make(map[string]int)
// For each letter, add to that key
for i := 0; i < len(word); i++ {
wordMap[string(word[i])]++
}
// In the end you have a map of each letter.
How could I apply this in C++?
How could I apply this in C++?
It could look rather similar to your Go code.
// Word map of char: int values
// (strings would be overkill, since you know they are a single character)
auto wordMap = std::map<char,int>{};
// For each letter, add to that key
for ( char c : word )
wordMap[c]++;
}
Here is the unicode version of Drew Dormann's answer:
#include <locale>
#include <codecvt>
std::string word = "some unicode: こんにちは世界";
std::map<char32_t, uint> wordMap;
std::wstring_convert<std::codecvt_utf8<char32_t>, char32_t> converter;
for (auto c : converter.from_bytes(word)) {
wordMap[c]++;
}
for (const auto [c, v] : wordMap) {
std::cout << converter.to_bytes(c) << " : " << v << std::endl;
}
I wrote an article about this which can be checked out here. Below i have given 2 versions of the program. Version 1 keeps track of the character count in alphabetical order. But sometimes(in case) you want the character count in insertion order for which you can use Version 2.
Version 1: Get character count in ͟a͟l͟p͟h͟a͟b͟e͟t͟i͟c͟a͟l͟ ͟o͟r͟d͟e͟r͟
#include <iostream> //needed for std::cout, std::cin
#include <map> //needed for std::map
#include <iomanip> //needed for formating the output (std::setw)
int main()
{
std::string inputString; //user input will be read into this string variable
std::cout << "Enter a string: " << std::endl;
std::getline(std::cin, inputString);
//this map maps the char to their respective count
std::map < char, int > charCount;
//iterate through the inputString
for (char & c: inputString)
{
charCount[c]++;//increment the count for character c
}
std::cout << "Total unique characters are: " << charCount.size() << std::endl;
std::cout << "------------------------------------" << std::endl;
std::cout << "Character" << std::setw(10) << "Count" << std::endl;
std::cout << "------------------------------------" << std::endl;
for (std::pair < char, int > pairElement: charCount)
{
std::cout << std::setw(4) << pairElement.first << std::setw(13) << pairElement.second << std::endl;
}
return 0;
}
Version 2: Get character count in i͟n͟s͟e͟r͟t͟i͟o͟n͟ ͟o͟r͟d͟e͟r͟
#include <iostream>
#include <map>
#include <iomanip>
int main()
{
std::string inputString;
std::cout << "Enter a string: " << std::endl;
std::getline(std::cin, inputString);
std::map < char, int > charCount;
for (char & c: inputString)
{
charCount[c]++;
}
std::cout << "Total unique characters are: " << charCount.size() << std::endl;
std::cout << "------------------------------------" << std::endl;
std::cout << "Character" << std::setw(10) << "Count" << std::endl;
std::cout << "------------------------------------" << std::endl;
std::size_t i = 0;
//just go through the inputString instead of map
for(char &c: inputString)
{
std::size_t index = inputString.find(c);
if(index != inputString.npos && (index == i)){
std::cout << std::setw(4) << c << std::setw(13) << charCount.at(c)<<std::endl;
}
++i;
}
return 0;
}
I'm a beginner and I have a question(somehow silly and stupid :) )...Today I decided to challenge myself and I came around the challenge that wanted me to create a program that ciphers (or encrypts) the message using the substitution cipher method...I solved the challenge by myself but mine is way different than the solution itself...I just want to know which one is better and why? and also is there anything I missed in my own code?
So here is the code I've written:
#include <iostream>
#include <string>
using namespace std;
int main()
{
string secretMessage {};
string alphabet {"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"};
string key {"XZNLWEBGJHQDYVTKFUOMPCIASRxznlwebgjhqdyvtkfuompciasr"};
cout << "Enter your secret message: ";
getline(cin, secretMessage);
//Encryption
for(size_t i{0}; i<secretMessage.length(); ++i){
for(size_t j{0}; j<alphabet.length(); ++j){
if (secretMessage.at(i) == alphabet.at(j)){
secretMessage.at(i) = key.at(j);
break;
}
}
}
cout << "Encrypting The Message..." << endl;
cout << "Encrypted Message: " << secretMessage << endl;
//Decryption
for(size_t i{0}; i<secretMessage.length(); ++i){
for(size_t j{0}; j<key.length(); ++j){
if (secretMessage.at(i) == key.at(j)){
secretMessage.at(i) = alphabet.at(j);
break;
}
}
}
cout << "\nDecrypting The Encryption..." << endl;
cout << "Decrypted: " << secretMessage << endl;
return 0;
}
And here is the solution:
#include <iostream>
#include <string>
using namespace std;
int main()
{
string secretMessage {};
string alphabet {"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"};
string key {"XZNLWEBGJHQDYVTKFUOMPCIASRxznlwebgjhqdyvtkfuompciasr"};
string encryptedMessage {};
string decryptedMessage {};
cout << "Enter your secret message: ";
getline(cin, secretMessage);
cout << "\nEncrypting Message..." << endl;
//Encryption
for(char c:secretMessage){
size_t position = alphabet.find(c);
if (position != string::npos){
char newChar {key.at(position)};
encryptedMessage += newChar;
} else{
encryptedMessage += c;
}
}
cout << "Encrypted Message: " << encryptedMessage << endl;
//Decryption
cout << "\nDecrypting Message..." << endl;
for(char c:encryptedMessage){
size_t position = key.find(c);
if (position != string::npos){
char newChar {alphabet.at(position)};
decryptedMessage += newChar;
} else{
decryptedMessage += c;
}
}
cout << "Decrypted Message: " << decryptedMessage << endl;
return 0;
}
Note:I have also included the decryption part too
I find both code snipets rather complex.
Please have a look at this more easy solution
#include <iostream>
#include <string>
#include <algorithm>
int main()
{
// The encoding alphabet and key
constexpr std::string_view alphabet{ "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ _" };
constexpr std::string_view key{ "ZYXWVUTSRQPONMLKJIHGFEDCBAzyxwvutsrqponmlkjihgfedcba_ " };
// String to encrypt
std::string message{"Hello world"};
// Here we will store the result
std::string result;
std::transform(message.begin(), message.end(), std::back_inserter(result), [&key, &alphabet](const char c)
{ size_t pos{ alphabet.find(c) }; return (pos != std::string::npos) ? key[pos] : '_'; });
// Show result
std::cout << "\nEncrypted: " << result << "\n";
message = result;
result.clear();
std::transform(message.begin(), message.end(), std::back_inserter(result), [&key, &alphabet](const char c)
{ size_t pos{ alphabet.find(c) }; return (pos != std::string::npos) ? key[pos] : '_'; });
// Show result
std::cout << "\nDecrypted: " << result << "\n";
return 0;
}
This is using more modern C++ language elements. Encrypting and decrypting is implemented via one std::transform statement each.
Of course you should never use such encoding in real live, because the key is visible in the exe file.
Anyway, maybe it helps you to have some more ideas . . .
I've been trying to get this Hangman using functions (from Michael Dawson's book) program to work, but I have this one error that I don't really understand. I realize my code code could have a variety of bad practices, but please go easy on me as I am a newb. I feel like I am almost there but I'm having trouble figuring out this one error. I am using CodeBlocks. The error is:
32|error: no match for call to '(std::__cxx11::string {aka std::__cxx11::basic_string}) (std::__cxx11::basic_string::size_type, char)'|
//Hangman from Michael Dawson's code
//Uses functions to create the program
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <ctime>
#include <cctype>
using namespace std;
//FUNCTION DECLARATION
string pickword();
char playerGuess();
void isitinthere();
char guess = 0;
string soFar = "word";
string used = "";
int wrong = 0;
int main()
{
const int MAX_WRONG = 8;
string WORD = pickword();
soFar = WORD;
soFar(WORD.size(), '-');
used = "";
cout << "Welcome to Hangman! Godspeed!" << endl;
while ((wrong < MAX_WRONG) && (soFar != WORD))
{
cout << "\n\nYou have " << (MAX_WRONG - wrong);
cout << " incorrect guesses left.\n";
cout << "\nYou've used the following letters:\n" << used << endl;
cout << "\nSo far, the word is:\n" << soFar << endl;
}
playerGuess();
while (used.find(guess) != string::npos)
{
cout << "\nYou've already guessed " << guess << endl;
cout << "Enter your guess: ";
cin >> guess;
guess = toupper(guess);
}
used += guess;
isitinthere();
if (wrong == MAX_WRONG)
{
cout << "\nYou've been hanged!";
}
else
{
cout << "\nYou guessed it!";
}
cout << "\nThe word was " << WORD << endl;
return 0;
}
//FUNCTION DEFINITION
string pickword()
{
srand(static_cast<unsigned int>(time(0)));
vector<string> words;
words.push_back("INDUBITABLY");
words.push_back("UNDENIABLY");
words.push_back("CRUSTACEAN");
words.push_back("RESPONSIBILITY");
words.push_back("MISDEMEANOR");
words.push_back("FORENSIC");
words.push_back("BALLISTIC");
words.push_back("PARADIGM");
words.push_back("TROUBARDOR");
words.push_back("SUPERCALIFRAGILISTICEXPIALLADOCIOUS")
random_shuffle(words.begin(), words.end());
theword = words[0];
return theword;
}
char playerGuess()
{
cout << "\n\nEnter your guess: ";
cin >> guess;
guess = toupper(guess);
return guess;
}
void isitinthere()
{
if (WORD.find(guess) != string::npos)
{
cout << "That's right! " << guess << " is in the word.\n";
for (int i = 0; i < WORD.length(); ++i)
{
if (WORD[i] == guess)
{
soFar[i] = guess;
}
}
}
else
{
cout << "Sorry, " << guess << "isn't in the word. \n";
++wrong;
}
}
Thanks in advance for your help!
Here is a simple program that should solve your question.
#include <iostream>
#include <string>
#include <vector>
#include <cstdlib>
#include <ctime>
#include <algorithm>
#include <cctype>
// since you must have function here are some
bool removeGuessFromWord(std::string& word, const char guess);
bool isGuessInWord(const std::string& word, const char guess);
bool hasAlreadyGuessed(const std::vector<char>& gussList, const char guess);
// this is a simple program that should solve your question. It is not optimized for speed or efficency.
int main()
{
std::vector<std::string> wordList = {"dog","cat","rat"}; // vector of words to select from and use as the word in hangman
std::vector<char> guessList; // empty vector of gusses
// Note that I assume a MAX_GUESS_COUNT of 0 means no guesses are allowed
const unsigned int MAX_GUESS_COUNT = 4U; // number of guesses your allowed
std::srand(time(0)); // use current time as seed for random generator
std::string word = wordList.at(std::rand()%wordList.size()); // get a random word in the list
std::string letersLeft = word; // keep track of what letters will still need to remove
std::cout << "Welcome to Hangman! Godspeed!" << std::endl;
char guess = 0;
for(unsigned int numBadGusses=0U; numBadGusses<MAX_GUESS_COUNT && letersLeft.size()>0U; guess = 0)
{
std::cin>>guess;
if(std::isprint(guess) == 0)
{
// may want more error checking
std::cout << "You ented a non-printable charecter" << std::endl;
}
else if(isGuessInWord(word, guess))
{
// this was a good guess because the charecter is still in the word
// so remove all the remaining chars of this type from the word
if( removeGuessFromWord(letersLeft,guess) )
{
std::cout << guess << " was a good guess" << std::endl;
}
else
{
std::cout << guess << " was a good guess, but you already guessed it once" << std::endl;
}
}
else if(hasAlreadyGuessed(guessList, guess))
{
std::cout << "You've already guessed " << guess << std::endl;
}
else
{
// this was a new bad guess
guessList.push_back(guess);
numBadGusses++; // Note that this isn't technicly needed and could use size of vector
std::cout << guess << " was a bad guess" << std::endl;
}
}
if(letersLeft.size() == 0U)
{
std::cout<<"You Win"<<std::endl;
}
else
{
std::cout<<"You Lose"<<std::endl;
}
std::cout << "The word was "<< word << std::endl;
return 0;
}
bool removeGuessFromWord(std::string& word, const char guess)
{
return word.erase(std::remove(word.begin(), word.end(), guess), word.end()) != word.end() ? true : false;
}
bool isGuessInWord(const std::string& word, const char guess)
{
return word.find(guess) != std::string::npos ? true: false;
}
bool hasAlreadyGuessed(const std::vector<char>& gussList, const char guess)
{
return std::find(gussList.begin(), gussList.end(), guess) != gussList.end() ? true: false;
}
User inputs a string in form of
length=10 width=15
The task is to find the length's and width's value in such a string(and assign them to variables). So, how can I find those two numbers? What functions/methods should I use? Can you guys just give me an idea?
Regular expressions are fun and are usually not acceptable as homework solutions for introductory classes.
match[1] and match[2] are the numerical portion of the string that you are interested in. You'll probably want to pass them to stoi() if you need to manipulate them as integers.
Code
#include <iostream>
#include <regex>
int main() {
std::string s("length=10 width=15");
std::regex re("length=([0-9]+) width=([0-9]+)");
std::smatch match;
if (regex_match(s, match, re)) {
std::cout << "length: " << match[1] << "\n";
std::cout << "width: " << match[2] << "\n";
}
}
Output
length: 10
width: 15
use stringstream:
#include <string>
#include <iostream>
#include <sstream>
#include <map>
using namespace std;
int main()
{
stringstream ss;
ss.str("length1=10 width=15 length2=43543545");
map<string, int> resMap;
string key;
int val;
while (ss.peek() != EOF) {
if (isalpha(ss.peek())) {
char tmp[256];
ss.get(tmp,streamsize(256),'=') ;
key = tmp;
} else if (isdigit(ss.peek())) {
ss >> val;
resMap.insert(pair<string, int>(key,val));
} else {
ss.get();
}
}
cout << "result:\n";
for (map<string, int>::iterator it = resMap.begin(); it != resMap.end(); ++it) {
cout << "resMap[" << it->first<< "]=" << it->second << endl;
}
getchar();
return 0;
}
For some reason it skips over the first input an goes straight to the second one.
#include<iostream>
#include<string>
using namespace std;
int stringWork()
{
const int LENGTH = 40;
char firstString[LENGTH], secondString[LENGTH];
cout << "Enter First String: ";
//it skips over this following line
cin.getline(firstString, LENGTH);
cout << "Enter Another String: ";
cin.getline(secondString, LENGTH);
if (strcmp(firstString, secondString) == 0)
cout << "You entered Same string two times\n";
else
cout << "The two strings you entered are not the same\n";
system("pause");
return 0;
}
int main()
{
stringWork();
return 0;
}
it only allows input for one string
This piece of code works on my machine just fine. However, please do change #include <string> to #include <string.h> or #include <cstring>, and add #include <stdlib.h> or #include <cstdlib>.
Fix the code like this:
#include <iostream>
#include <string>
void stringWork()
{
const int LENGTH = 40;
char firstString[LENGTH], secondString[LENGTH];
std::cout << "Enter First String: " << std::flush;
std::cin.getline(firstString, LENGTH);
std::cout << "Enter Another String: " << std::flush;
std::cin.getline(secondString, LENGTH);
if (strcmp(firstString, secondString) == 0) {
std::cout << "You entered Same string two times." << std::endl;
} else {
std::cout << "The two strings you entered are not the same." << std::endl;
}
}
int main()
{
stringWork();
return 0;
}
Some notes about my version of your code:
Please don't use using namespace std.
Use std::flush to flush the characters in the output stream. This is necessary because usually the characters are only flushed with std::endl or in some implementations if you add a newline character.
Avoid mixing C and C++ code as you did. Use the std::getline method to read a line directly into a std::string. Shown in the next example.
Please care about your code style, especially if you post it in the public.
A even better implementation would avoid any C code and use just C++:
#include <iostream>
#include <string>
void stringWork()
{
std::cout << "Enter First String: " << std::flush;
std::string firstString;
std::getline(std::cin, firstString);
std::cout << "Enter Another String: " << std::flush;
std::string secondString;
std::getline(std::cin, secondString);
if (firstString == secondString) {
std::cout << "You entered Same string two times." << std::endl;
} else {
std::cout << "The two strings you entered are not the same." << std::endl;
}
}