题解 | #查找#

#include<bits/stdc++.h>
using namespace std;

int main()
{
	set<int> s;
	//write your code here......
	int n, m;

	cin >> n >> m;

	for (int i = 0; i < n; ++i)
	{
		int num;
		cin >> num;
		s.insert(num);
	}	

	set<int>::iterator it;
	for (int i = 0; i < m; ++i)
	{
		int x;
		cin >> x;

		it = s.upper_bound(x);

		if (it != s.end())
		{
			cout << *it << endl;
		}
		else 
		{
			cout << -1 << endl;
		}
	}
	
	return 0;
}

使用upper_bound()

upper_bound(data)用于寻找大于data，返回iterator