需要iostream头文件

#include <stdio.h>
#include <iostream>
#include <algorithm>
using namespace std;

int main()
{
    int a[5] = {1, 5, 4, 2, 3};
    sort(a, a + 5, greater<int>()); //less<int>()
    for(int i = 0; i < 5; ++i)
        printf("%d ", a[i]);
    return 0;
}
//output
//5 4 3 2 1

sort 内置类型排序