Leetcode-Solutions/CelebrityProblem.cpp at main · rushangchandekar/Leetcode-Solutions · GitHub

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

int celebrity(vector<vector<int>>& arr) {
    int n = arr.size();
    stack<int> s;
    for(int i = 0; i < n; i++){
        s.push(i);
    }

    while(s.size() > 1){
        int i = s.top();
        s.pop();

        int j = s.top();
        s.pop();

        if(arr[i][j] == 0){
            s.push(i);
        }else{
            s.push(j);
        }
    }

    int celeb = s.top();

    for(int i = 0; i < n; i++){
        if(i != celeb){
            if(arr[i][celeb] == 0 || arr[celeb][i] == 1){
                return -1;
            }
        }
    }

    return celeb;

}
int main() {
    vector<vector<int>> arr = {{0, 1, 0},
                                {0, 0, 0},
                                {0, 1, 0}};
    int ans = celebrity(arr);

    cout << "celebrity = " << ans << endl;

    return 0;
}