c++ - Why my string isn't taking the input correctly the second time? -

my code takes string , displays index position letters after space shows odd indexed letters. if give input hacker should give hce akr. here code isn't giving me right answer second input. on giving 2nd input rank should give rn ak. instead of gives k .here misses r.

---

#include <cmath> #include <cstdio> #include <vector> #include <iostream> #include <algorithm> using namespace std;  void f(string a) {      string odd,even;     for(int i=0; a[i] != '\0'; i++) {         if(i % 2 == 0) {             = + a[i];         } else {             odd = odd + a[i];         }     }      cout << << " " << odd << "\n";//<<<<<<i think \n         //problem need \n.i obeserved on removing \n, codes       // works correctly. }  int main() {     /* enter code here. read input stdin. print output stdout */     string str;     int t;     cin >> t;      for(int i=0; < t; i++) {         std::cin.ignore();         getline(cin, str);         f(str);     }      return 0; } 

you should move std::cin.ignore() outside of loop. getline consumes newline character, first input leaves (cin>>t).

when read e.g. int or char, newline character after input stays in input stream. doing getline read newline character , call cin.ignore() consume newline character. each getline() consumes whole line including newline character, don't have call cin.ignore() , if do, per default consume 1 character, here 'r'.