Get Signature [NCTU Floor 3]

#include <iostream>
#include <vector>
using namespace std;

int solve(vector <int> celeb, int n){
    int result = -1, count, flagCeleb;
    for(int i = 1; i <= n; i++){
        vector <bool> flag(n + 1, false);
        count = 0;
        int temp = i;
        while(!flag[celeb[temp]]){
            flag[celeb[temp]] = true;
            temp = celeb[temp];
            count++;
            if(count > result){
                result = count;
                flagCeleb = i;
            }
        }
    }
    return flagCeleb;
}

int main(){
    int n, a, b;
    vector <int> celeb;
    while(cin >> n){
        celeb.resize(n + 1);
        for(int i = 0; i < n; i++){
            cin >> a >> b;
            celeb[a] = b;
        }
        cout << solve(celeb, n) << endl;
        celeb.clear();
    }
    return 0;
}