upper_bound下确界

//uppper_bound上确界找出首个大于某值的元素
#include<algorithm>
#include<iostream>

using namespace std;

int main()
{
    int a[] = {23, 9, 7, 2, 3, 4};
    int len = sizeof(a)/int (a);
    int *x = upper_bound(a, a+len, 7);

    cout<<"不小于7的上确界元素为"<<*x<<endl;

    system("pause");

    return 0;
}