Programación Competitiva

#include<bits/stdc++.h>
using namespace std;

int n;
map<int, int> m;
vector<int> v;

int main() {
    while(scanf("%d", &n) == 1) {
        if(m[n] == 0) v.push_back(n);
        m[n]++;
    }
    for(int i = 0; i < v.size(); i++) {
        printf("%d %d\n", v[i], m[v[i]]);
    }
}