Gyu

Geg.cpp

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostrea
#include <algorithm>
using namespace std;
int repeatedNumber( vector<int> &A) {
    int n = A.size();
    if(n == 0) return -1;
    if(n <= 2) return A[0];
    int c1 = 0, c2 = 0, f = 0, s = 0;
    for(int i = 0; i < n; i++) {
        if(A[i] == f) {
            c1++;
        }
        else if(A[i] == s) {
            c2++;
        }
        else if(c1 == 0) {
            c1 = 1;
            f = A[i];
        }
        else if(c2 == 0) {
            c2 = 1;
            s = A[i];
        }
        else {
            c1--;
            c2--;
        }
    }
    c1 = 0;
    c2 = 0;
    for(int i = 0; i < n; i++) {
        if(A[i] == f) c1++;
        if(A[i] == s) c2++;
    }
    if(c1 > n/3) return f;
    else if(c2 > n/3) return s;
    return -1;
}
   
int main() {
    int n;
    std::cin>>n;
     vector <int> A(n);
    for(int t=0;t<n;t++)
       std::cin>>A[t];
    std::cout<<repeatedNumber(A);  
    return 0;
}