应该怎么用map找出次数最多的元素

例如这个题目 应该怎么做
After celebrating the midcourse the students of one of the faculties of the Berland State University decided to conduct a vote for the best photo. They published the photos in the social network and agreed on the rules to choose a winner: the photo which gets most likes wins. If multiple photoes get most likes, the winner is the photo that gets this number first.

Help guys determine the winner photo by the records of likes.

Input
The first line of the input contains a single integer n (1 ≤ n ≤ 1000) — the total likes to the published photoes.

The second line contains n positive integers a1, a2, ..., an (1 ≤ ai ≤ 1 000 000), where ai is the identifier of the photo which got the i-th like.

Output
Print the identifier of the photo which won the elections.

Examples
input
5
1 3 2 2 1
output
2
input
9
100 200 300 200 100 300 300 100 200
output
300

用元素做map的key 遍历数据 把数据做key对应的map value加一 最后统计

http://www.cnblogs.com/zhangchengc919/p/5278969.html

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

int _tmain(int argc, _TCHAR* argv[])
{
    map<int, int> _map;
    int n = 0;
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        int x = 0;
        cin >> x;
        _map[x]++;
    }
    int max = 0;
    int maxval = 0;
    for (map<int, int>::iterator ltr = _map.begin(); ltr != _map.end(); ltr++)
    {
        if (ltr->second >= max)
        {
            maxval = ltr->first;
            max = ltr->second;
        }
    }
    cout << maxval;
    return 0;
}

帮你写了一个，休再说看不懂。