题解 | #查找#

#include<iostream>
#include<algorithm>
using namespace std;
int main(){
    int n,m;
    while(cin>>n){
        int a[n];
        for(int i=0;i<n;i++){
            cin>>a[i];
        }
        sort(a,a+n);
        cin>>m;
        int b[m];
        for(int i=0;i<m;i++){
            cin>>b[i];
           int low=0;int high=n-1;
           int mid;
            int flag=0;
           while(low<=high){
               mid=(low+high)/2;
               if(a[mid]==b[i]){
                   cout<<"YES"<<endl;
                   flag=1;
                   break;
               }else if(a[mid]>b[i]){
                   high=mid-1;
               }else{
                   low=mid+1;
               }
           }
            if(flag==0){
                cout<<"NO"<<endl;
            }
        }
    }
}