Getline keeps on getting newline character. How can I avoid this?

Question

Basically I first takes an integer as input and then test case follows. My each test case is an string. I am suppose to print the string back if the starting patten of string matches "HI A" and it is case-insensitive. I wrote the code below to accomplish to this. My problem is that when I press enter after each input, getline takes newline character as new input. I have tried to tackle this by using extra getline after each input but the issue is still there. Program gets stuck in the loop even though I have put a break condition. What am I doing wrong?

#include <iostream>
#include <string>
using namespace std;
int main(){
    int N;
    cin >>N;
    string nl;
    getline(cin,nl);
    for (int i=0;i<N;i++){
        string s;
        getline(cin,s);
        //cout <<"string"<<s<<endl;
        int flag=0;
        if ((s.at(0)=='h'||s.at(0)=='H')&&(s.at(1)=='i'||s.at(1)=='I')&&(s.at(2)==' ')&&(s.at(3)=='a'||s.at(3)=='A')) flag=1;

        if (flag==1) cout << s;
        //cout << "not " <<s;
        string ne;
        cout << "i="<< i<<endl;
        if (i==N-1) {break;}
        getline(cin,ne);

    }
}

Here is sample input:

5
Hi Alex how are you doing
hI dave how are you doing
Good by Alex
hidden agenda
Alex greeted Martha by saying Hi Martha

Output should be:

Hi Alex how are you doing

Answer 1

ignore() function does the trick. By default, it discards all the input suquences till new line character.

Other dilimiters and char limit can be specified as well.

http://www.cplusplus.com/reference/istream/istream/ignore/

In your case it goes like this.

    cin >> N;
    cin.ignore();

Answer 2

I am writing this answer with the hopes that it may help someone else out there that wants a very simple solution to this problem.

In my case the problem was due to some files having different line endings such as '\r' vs. '\n'. Everything worked fine in windows but then it failed in Linux.

The answer was actually simple. I created a function removeNewLineChar after each line was read in. That way the char was removed. The removeNewLineChar takes in the line that was read in and copies it over character by character into a new string but it avoids copying either of the newline characters.

Here is a full explanation of how that works.

C++ getline reads in the newline character and how to avoid it