int main()
{
int number_of_words = 0;
int prevnum = -1;
string previous = "";
string current;
while (cin >> current)
{
++number_of_words;
if (previous == current)
{
cout << "word number: " << number_of_words << "\n"
<< "Repeated Word: " << current << "\n";
previous = current;
}
else while (prevnum == number_of_words)
{
number_of_words = 0;
prevnum = 0;
break;
}
}
}
In this app, I'm trying to display repeated words and their position number within the text. When it finishes running the inputted statement, it keeps the number_of_words for the next input. I tried fixing this with the else while condition, at which the while loop would break.
What should I do differently?
Does the while loop run again after breaking or would i need to put this into another while loop that prompts the user on whether or not they are ready to type in some text?
*this is Ch. 3 so I'm guessing I should just move on but was curious
Try this:
#include <sstream>
#include <string>
#include <iostream>
using namespace std;
int main()
{
int number_of_words;
string previous;
string current, input;
while (true)
{
previous = "";
number_of_words = 0;
cout << "\nWrite the data\n";
getline(std::cin, input);
stringstream ss;
ss << input;
while (ss >> current)
{
++number_of_words;
if (previous == current)
cout << "word number: " << number_of_words << "\n"
<< "Repeated Word: " << current << "\n";
previous = current;
}
}
}
I have used an stringstream variable to break every loop of input, so i could reset the counters.
Related
Why my code is not executing and showing me error ?? Im getting error on this line
while (getline(s, word, ' , '))
my Code is below:
#include <fstream>
#include <string>
#include <string.h>
#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;
// first we define a class that will represent all the candidates
class Candidate
{
string name;
int votes;
public:
Candidate()
{
name = "";
int votes = 0;
}
Candidate(string cand_name, int vote_count)
{
name = cand_name; votes = vote_count;
} string getName() { return name; } int getVotes() { return votes; } void get_details() { cout << name << ", " << votes << endl; }
//Following member method is used to increment the vote count
void vote_this_candidate() { votes++; }
};
int main()
{
cout << "Welcome to Student President Voting System!!!" << endl;
Candidate allCandidates[100];
int totalVotes = 0;
// File pointer fstream fin; // Open an existing file
fstream fin;
fin.open("candidantes.txt", ios::in); // Read the Data from the file // as String Vector
vector <string> row;
string line, word, temp; int index = 0; // Following while loop will iterate for each line in the file
while (fin >> temp) {
row.clear(); // read an entire row and // store it in a string variable 'line'
getline(fin, line); // used for breaking words
string s(line); // read every column data of a row and // store it in a string variable, 'word'
while (getline(s, word, ' , '))
{ // adding the splitted words to row
row.push_back(word);
} allCandidates[index] = Candidate(row[0], stoi(row[1])); totalVotes += stoi(row[1]); index++;
}
string name = ""; cout << "\nPlease enter the name of the candidante you want to vote : ";
getline(cin, name); int cand_no = -1; string userChoice; int i = 0; //Now we find the candidante with the same inputted name
while (i < index) {
if (allCandidates[i].getName() == " " + name) {
cand_no = i; cout << "Do you want to vote this candidante [y/n] : ";
cin >> userChoice; //After finding the candidate just ask the user to vote the candidante
if (userChoice == "y") { //to vote just call the member method that increments the vote count
allCandidates[cand_no].vote_this_candidate(); totalVotes++; cout << endl << "You successfully voted to " << name << " Thanks for voting!!!" << endl;
}
else { cout << "You didn't vote!!!" << endl; } break;
}
i++;
} if (cand_no == -1) {
cout << "Candidante not found!!! Do you like to add this candidate [y/n]: ";
cin >> userChoice; if (userChoice == "y") { allCandidates[index + 1] = Candidate(name, 1); totalVotes++; index++; }
}
//To show top five candidates we first sort the array with lambda
std::sort(allCandidates, allCandidates + 10, [](Candidate a, Candidate b) -> bool { return a.getVotes() > b.getVotes(); });
//then we show only first five candidates
cout << endl << "These are top 5 candidantes so far : " << endl;
for (int i = 0; i < 5; i++)
{
cout << i + 1 << ","; allCandidates[i].get_details();
} cout << endl << "Total studnets voted: " << totalVotes;
}
Problem is here:
string s(line);
while (getline(s, word, ' , '))
because getline has no overload that takes a std::string as its first parameter.
However, there is an overload that takes a stringstream, so you can do:
stringstream ss(line);
while (getline(ss, word, ' , '))
Also, ' , ' won't do what you think. Perhaps you meant ','.
Finally, int votes = 0; in your Candidate() constructor should just be votes = 0;. As it is, you are just declaring, initialising and then discarding a local variable.
The problem is that the compiler is telling you that the parameters you've given don't match a definition of the function. In your case I believe the problem is that you've given it 3 characters instead of 1 in the character portion (remember, a space is also a character). Try changing ' , ' to ','
I'm new in c++. I want to print [ at the beginning and ] at the end of stream when i print some string by keyboard. also it must be print , between each of string. notice number of strings is unknown. for example if i print in screen: ggg hhh jj klk the result of program must be: [ggg,hhh,jj,klk]. I've tried this:
string cur = "";
while (cin >> cur)
{
cout << "[" << cur << ",";
}
but this wrong!
Edit: by #NadavS 'sanswer we have this:
by #asmmo 's answer we have this:
but my expectation is:
sss ddd fff ggg
[sss,ddd,fff,ggg]
ddf hjh lk iop
[ddf,hjh,lk,iop]
If your compiler supports it, std::experimental::ostream_joiner does this.
#include <algorithm>
#include <experimental/iterator>
#include <iostream>
#include <iterator>
int main()
{
std::cout << "[";
std::copy(std::istream_iterator<std::string>(std::cin),
std::istream_iterator<std::string>(),
std::experimental::make_ostream_joiner(std::cout, ","));
std::cout << "]";
}
Outputs [ggg,hhh,jj,klk] from ggg hhh jj klk
I always program these loops with some code duplication. There are other solutions, but the general concept is separating the first case from the others.
string cur = "";
cout << '[';
if (cin >> cur) {
cout << cur;
while (cin >> cur) {
cout << ',' << cur;
}
}
cout << ']';
Demo
edit: Despite the fact this solution works, the question asker views his "stdin" and "stdout" in "the same window", so the output doesn't look pretty, and the solution should be to store a list of strings from cin and only then start printing.
string cur = "";
std::vector<string> all_strings;
while (cin >> cur) {
all_strings.push_back(cur);
}
cout << '[';
bool first = true;
for (auto& a : all_strings) {
if (first) {
first = false;
} else {
cout << ", ";
}
cout << a;
}
cout << ']';
You must make the loop stop at some point but you didn't. So you can send an EOF at the end of your inputs to make it stops (using ctrl+z on windows and ctrl+D on other OSs). And to get the wanted format change your loop to
int main()
{
string cur = "";
cout << "[ ";
if( cin >> cur) cout << cur;
while (true)
{
cin >> cur;
if( !cin )
{
cout << "]" ;
break;
}
cout << "," << cur;
}
}
If you want to separate the inputs and outputs, you can do the following
#include <iostream>
#include <vector>
#include <string>
int main()
{
std::vector<std::string> vec;
std::string temp{};
while(std::cin >> temp) vec.push_back(temp);
std::cout << "\n[ " << vec[0];
for(int i {1}; i < vec.size(); i++) std::cout << ", " << vec[i];
std::cout << "]";
}
To make cin stop inputting on pressing Enter, use std::cin.peek() which can know the next character without taking it from the stream, as follows
#include <iostream>
#include <vector>
#include <string>
int main()
{
std::vector<std::string> vec;
std::string temp{};
while(std::cin >> temp && !(std::cin.peek() == '\n')) vec.push_back(temp);
std::cout << "\n[" << vec[0];
for(int i {1}; i < vec.size(); i++) std::cout << ", " << vec[i];
std::cout << "]";
}
c++ Microsoft visual studio on a windows.
im very new to coding. currently going through Programming -- Principles and Practice Using C++ by Stroupstrup and I came across a difficulty. I am to create a "score chart" with vector name and vector score from the user input. I used for-loop to get the input. now I am to modify the program so that with 2nd input from the user I can search the list and "cout<<" the score for a person. the problem is the the program completely ignores the 2nd "cin>>" command.
I search online and could not find a reasonable answer to this problem. Is there any special interaction between a for-loop input being terminated and another input (not looped)
syntax:
#include "stdafx.h"
#include <iostream>
#include <vector>
#include <string>
using namespace std;
int main()
{
vector<string> name;
vector<int> score;
string temp2;
int i;
for (string temp; cin >> temp >> i;) //input terminated with "Ctrl+Z"
name.push_back(temp), score.push_back(i);
for (int i = 0; i < name.size(); ++i) {
for (int j = i + 1; j < name.size(); ++j) {
if (name[i] == name[j]) {
name[j] = "error";
score[j] = 0;
}
}
}
for (int i = 0; i < name.size(); ++i) {
cout << name[i] << "------" << score[i] << "\n";
}
cout << "name"; //this line shows in the console
cin >> temp2; //but I cannot prompt the user to input again?
return 0;
}
CTRL-Z is interpreted as "End-Of-File", such that any subsequent access to this stream will not read in items any more. The only secure way is to change program logic such that the list of names is terminated by, let's say "END", and not a CTRL-Z. Then you can continue in a save manner.
Often input from a terminal is read in line by line and parsed afterwards. This makes error handling easier. See the following code following such an approach:
#include <sstream>
int main() {
string line;
map<string,int> scoreboard;
cout << "enter name score (type END to finish):" << endl;
while (std::getline(cin, line) && line != "END") {
stringstream ss(line);
string name;
int score;
if (ss >> name >> score) {
scoreboard[name] = score;
} else {
cout << "invalid input. Type END to finish" << endl;
}
}
cout << "enter name:" << endl;
string name;
if (cin >> name) {
auto item = scoreboard.find(name);
if (item != scoreboard.end()){
cout << "score of " << name << ":" << item->second << endl;
}
else {
cout << "no entry for " << name << "." << endl;
}
}
}
Using C++, I'm trying to make a hangman game to become better at using C++ and programming in general. Anyways, the issue I'm facing is that I'm not sure how to replace the dashes within a string with the letter the user has guessed.
I think my problem is with the fact the word chosen is randomly chosen from an array and I'm not sure how to go about finding the positions within the randomly chosen string which consists of the guessed character.
I have commented out the area that's causing the issue.
#include <iostream>
#include <array>
#include <string>
#include <stdlib.h>
#include <time.h>
#include <cstddef>
#include <algorithm>
using namespace std;
int main()
{
string words[3] = {"stack", "visual", "windows"};
string guess;
cout << "Welcome to hangman.\n";
cout << "\n";
srand(time(NULL));
int RandIndex = rand() % 3;
string selected = words[RandIndex];
for (int i = 1; i <= selected.size(); i++) {
cout << "_ ";
}
cout << "\n";
cout << "\nType in a letter: ";
cin >> guess;
cout << "\n";
if (selected.find(guess) != string::npos) {
/*for (int i = 1; i <= selected.size(); i++) {
if (selected.find(guess) != string::npos) {
cout << "_ ";
} else {
cout << guess << " ";
}
}*/
} else {
cout << "\nNay!\n";
cout << "\n";
}
cout << "\n";
cout << "\n";
system("PAUSE");
return 0;
}
I was thinking about using the replace() function but the problem I face here is that I'm not replacing the string within selected variable but sort of iterating through the word itself, if that made any sense whatsoever?
Use a second string, that is initialized with the underscores. If the find function doesn't return string::npos it returns the position in the string, and this is the same position you should change in the string with the underscores as well.
You actually need to use a second string to store the "guessed" string; this is because you need to keep track of all the guessed letters and display them.
something like :
string s ="test";
string t=""; //empty string
for(int i=0;i<s.size();i++)
t.append("_"); //initialize the guess string
cout<<t<<'\n';
char c;
cin >> c;
int pos = s.find(c); //get the first occurrence of the entered char
while(pos!=-1) //look for all occurrences and replaced them in the guess string
{
t.replace(pos,1,1,c);
pos = s.find(c, pos+1);
}
I think you need to maintain some extra state while looping - to keep track of which letters have / haven't been guessed.
You could add a new string current_state which is initially set to the same length as the word but all underscores. Then, when the player guesses a letter, you find all instances of that letter in the original word, and replace the underscore with the letter guessed, at all the positions found but in current_state.
First i would initialize a new string to show the hidden word:
string stringToDisplay = string( selected.length(), '_');
Then For each letter given by the user i would loop like this:
(assuming guess is letter)
size_t searchInitPos = 0;
size_t found = selected.find(guess, searchInitPos));
if (found == string::npos)
{
cout << "\nNay!\n";
cout << "\n";
}
while( found != string::npos)
{
stringToDisplay[found] = guess;
searchInitPos = found+1;
found = selected.find(guess, searchInitPos));
}
cout << stringToDisplay;
Hope this will help
I think it should be that:
string words[3] = {"stack", "visual", "windows"};
char guess;
string display;
cout << "Welcome to hangman.\n";
cout << "\n";
srand(time(NULL));
int RandIndex = rand() % 3;
string selected = words[RandIndex];
for (int i = 0; i < selected.size(); i++) {
display.insert(0, "_ ");
}
cout << display;
while(display.find("_ ") != string::npos) {
cout << "\n";
cout << "\nType in a letter: ";
cin >> guess;
cout << "\n";
bool flag = false;
for (int i = 0; i < selected.size(); i++) {
if (selected[i] == guess) {
display.replace(i*2, 1, 1, guess);
flag = true;
}
}
if (!flag) {
cout << "\nNay!\n";
cout << "\n";
} else {
cout << display;
}
}
#include <iostream>
#include <ctype.h>
using namespace std;
void isPalindrome();
int main()
{
char response;
isPalindrome();
cout << "Input another string(y/n)?" << endl;
cin >> response;
response = toupper(response);
if (response == 'Y')
isPalindrome();
return 0;
}
void isPalindrome()
{
char str[80], str2[80];
int strlength;
int j = 0;
int front, back;
bool flag = 1;
cout << "Input a string:" << endl;
cin.getline(str, 80);
strlength = strlen(str);
for (int i = 0; i < strlength; i++)
{
if (islower(str[i]))
str[i] = toupper(str[i]);
}
for (int i = 0; i < strlength; i++)
{
if (isalpha(str[i]))
{
str2[j] = str[i];
j++;
}
}
str2[j] = '\0';
front = 0;
back = strlength - 1;
for (int i = 0; i < j / 2; i++)
{
if (str2[front] != str2[back])
{
flag = 0;
break;
}
}
if (!(flag))
cout << "It is not a palindrome" << endl;
else
cout << "It's a palindrome" << endl;
cout << "str: " << str << " str2: " << str2 << " strlength: " << strlength << " j: " << j << endl;
cout << "front: " << front << " back: " << back << " flag: " << flag << endl;
}
I was just wondering if anybody could help explain to me why my code isn't working.
I can run it once just fine and I get the right answer, but when the prompt asks if I want to input another string and I type 'y', the prompt just skips over the input and terminates on it's own.
I tried cin.ginore('\n', 80), but that just gave me a bunch of blank lines. I added the bit of code at the end to check the values and they all go to 0 and drop the strings.
Maybe a link to a proper explanation of how the system handles memory?
edit:
I keep getting the same problem when running the input sequence a second time. The output looks like this:
Input a string:
Radar
It's a palindrome
Input another string(y/n)?
y
_ <- this being my cursor after pressing enter 3 times
I'll just re-build the program from scratch and try to do it without a function. I'd still appreciate a link to a page that explains how to process user input using modern c++.
The problem is with:
cin >> response;
This reads the user input y/n into the variable response but a newline is left in the input buffer which is picked by the getline function the isPalindrome function.
To fix this you need to remove the newline from the input buffer after you read the user response. You do it by using:
cin >> response;
std::cin.ignore(INT_MAX);
With the above fix you can retry the palindrome check just once. To make multiple retries possible you'll need a loop. I would recommend a do-while loop in your main as:
char response;
do {
isPalindrome();
cout << "Input another string(y/n)?" << endl;
cin >> response;
std::cin.ignore(INT_MAX);
response = toupper(response);
} while(response == 'Y');
You need a loop. There's no code that instructs the program to go back to the top.
char response = 'Y';
while (response == 'Y') {
isPalendrome();
cout << "Input another string(y/n)?" << endl;
cin >> response;
}
This isn't your entire program, just key elements that you need for a while loop. You should get an understanding of how while works and make this work for your program.
In contemporary C++ one would typically use standard library components for string processing:
#include <iostream>
#include <string>
int main()
{
std::string line1, line2, response;
do
{
std::cout << "First string: ";
if (!std::getline(std::cin, line1)) { /* error */ }
std::cout << "Second string: ";
if (!std::getline(std::cin, line2)) { /* error */ }
// check line1 and line2 for palindromy
std::cout << "Again (y/n)? ";
std::getline(std::cin, response);
} while (std::cin && (response == "y" || response == "Y"));
}