贓車查緝(Binary Sarch 二分搜尋法)

#include<bits/stdc++.h>
using namespace std;
int main(){
    int piece,piece2;
    string check_number;
    cin>>piece;
    string list[piece];
    for(int i=0;i<piece;i++){
        cin>>list[i];
    }
    sort(list,list+piece);
    cin>>piece2;
    for(int q=0;q<piece2;q++){
        cin>>check_number;

        //二分搜尋法實作
        int found =0;
        int L=0,R=piece-1,M;
        while(L<=R){
            M=int((L+R)/2);
            if(list[M]==check_number){
                found =1;
                break;}
            else if(list[M]>check_number){
                R=M-1;}
            else{L=M+1;}
        }
        if(found==1) cout<<"Y\n";
        else cout<<"N\n";
    }

    return 0;
}