题解 | #查找#

#include<bits/stdc++.h>
using namespace std;
int main(){
	set<int>s;
	//write your code here......
	int n, m, x;
    cin>>n>>m;
    for (int i = 0; i < n; i++) {
        cin>>x;
        s.insert(x);
    }
    while (m--) {
        cin>>x;
        auto it = s.upper_bound(x);
        if (it == s.end()) cout<<-1<<endl;
        else cout<<*it<<endl;
    }
	return 0;
}