为啥样例对，却不过，玄关

#include<bits/stdc++.h>
using namespace std;
const int N=1e6+10;
long long a[N];
long long q[N];
int main(){
    int n,m;

    cin >> n >> m;
    for(int i = 1; i <= n; i++){
        cin >> a[i];
    }

    for(int i = 1; i <= m; i++){
        cin>>q[i];
        int first=1,middle;
        int half,len;
        len = n;
        while(len > 0){

            half = len >> 1;
            middle = first + half;
            if(a[middle] < q[i]){    
                first = middle + 1;         
                len = len - half - 1; 
            }
            else{
                len = half;
            }        
        }
        if(a[first]!=q[i]){
            cout<<"-1 ";
        }else{
            cout<<i<<" ";
        }
    }

    return 0;
}