算法1

$O(n)$

C++ 代码

#include <iostream>
using namespace std;

const int N =10010;
int arr[N], n,t;

int main(){
    cin >> n;
    int ans =-1; int count = -1;
    for(int i = 0; i <n;i++){
        cin >> t;arr[t]++;
        if(arr[t] > count){ans = t;count = arr[t];
        }else if(arr[t] == count && ans > t){ ans = t;}
    }
    cout << ans<<endl;
    return 0;
}