Mirror Tree using maps and iterators and pairs

mirrorTree.cpp

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include<utility>
#include<map>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */ 
    map < pair<int,int>,char> my_map1;
    int N;
    cin>>N;
    int i,j,k;
    char d;
    for(k=0;k<N-1;k++)
    {
        pair<int,int> p;
        cin>>i>>j>>d;
        p=make_pair(i,j);
        my_map1[p]=d;
    }
    map < pair<int,int>,char> ::iterator it;
    for(k=0;k<N-1;k++)
    {
        pair<int,int> p;
        cin>>i>>j>>d;
        p=make_pair(i,j);
        it=my_map1.find(p);
        if(it==my_map1.end())
          break;
        if(my_map1.find(p)->second == d)
            break;
    }
    if(k<N-1)
        cout<<"no";
    else
        cout<<"yes";
    
    return 0;
}