HDU 1897 multiset的用法

#include<bits/stdc++.h>

using namespace std;

int main(){
    int t,a,b,c,x,cas=1;
    
    cin>>t;
    
    while(t--){
    	
        multiset<int > wine;
        
        wine.clear();
        
        scanf("%d%d%d",&a,&b,&c);
        
        printf("Case %d:\n",cas++);
        
        while(a--){
            scanf("%d",&x);
            wine.insert(x);
        }
        while(b--)
        {
            scanf("%d",&x);
            multiset<int >::iterator t=wine.lower_bound(x);
                if(t==wine.end()||*t-x>c)printf("-1\n");
                else
                {
                    printf("%d\n",*t);
                    wine.erase(t);
                }
        }
    }
    return 0;
}