c++ - I am trying to fill vector array with getline, what's wrong? -

i fill vector array lines don't same back. problem code?

using namespace std;  vector<string> calling(int n){     vector<string> file(n);     int a=0;      while(n){        getline(cin,file[a]);        cin.ignore();        a++;        n--;     }     return file; }  int main() {     int n;     cin >> n;     vector<string> hrml = calling(n);     int a=0;     while(n){         cout << hrml[a] <<endl;         a++;         n--;      }      return 0; } 

the input:

3 aaaa aaa aa bb b bbbb c cc ccc 

the output:

aaaa aaa aa bb b bbbb 

it's combination of few factors.

reading first number in input, 3, doesn't move "cursor" next line; moves past number. when next call getline, returns std::string of size 0, because grabs space between end of character , end of line, nothing.

then, because you're using number explicit number of strings read, you're reading 3 lines: "", "aaaa aaa aa", , "bb b bbbb".

hence output missing line of 'c''s.

the simplest solution here force call getline before call calling. (i've removed using namespace std; code because it's bad practice)

int main() {     int n;     std::cin >> n;     std::string line;     std::getline(std::cin, line); 

then, can rewrite calling not need integer parameter:

std::vector<std::string> calling(){     std::vector<std::string> file;     std::string line;     while(std::getline(std::cin, line)){         file.push_back(std::move(line));     }     return file; } 

(if you're testing in console, , need mark end of line, use ctrl+z on windows or ctrl+d on unix.)

which changes calling line this:

std::vector<std::string> hrml = calling(); 

or this, if you're using c++11 (and don't mind loss of explicitly visible type declaration):

auto hrml = calling(); 

and long we're here, can write better loop printing contents of our vector:

for(size_t = 0; < hrml.size(); i++) {     std::cout << hrml[i] << std::endl; } 

or, if we're using c++11:

for(std::string const& line : hrml) {     std::cout << line << std::endl; } 

and, if you're allowed change format of input file, can ditch reading of number in first place, yielding smaller , easier debug program:

#include<iostream> #include<string> #include<vector>  std::vector<std::string> calling(){     std::vector<std::string> file;     std::string line;     while(std::getline(std::cin, line)) {         file.push_back(std::move(line));     }     return file; }  int main() {     std::vector<std::string> hrml = calling();      for(std::string const& line : hrml) {         std::cout << line << std::endl;     }     return 0; }