QWQ 为什么改一点点就AC了

#include<bits/stdc++.h>
#define int long long
using namespace std;
int n;
bool flag[1000005];
bool check(int k){
    cout<<k<<endl;
    string s;
    cin>>s;
    if(s=="Male")return 1;
    if(s=="Female")return 0;
    if(s=="Vacant")exit(0);
}
signed main(){
    cin>>n;
    int l=0,r=n-1;
    flag[r]=check(r);
    while(l<=r){
        int mid=(l+r)>>1;
        flag[mid]=check(mid);
        if(((mid-l+1)&1)==(flag[mid]==flag[l])){
            l=mid;
        }
        else r=mid;
    }
}

#include<bits/stdc++.h>
using namespace std;
int n;
bool flag[1000005];
bool check(int k){
    cout<<k<<endl;
    string s;
    cin>>s;
    if(s=="Male")return 1;
    if(s=="Female")return 0;
    if(s=="Vacant")exit(0);
}
signed main(){
    cin>>n;
    int l=0,r=n-1;
    flag[r]=check(r);
    while(l<=r){
        int mid=(l+r)>>1;
        flag[mid]=check(mid);
        if(((r-mid+1)&1)==(flag[mid]==flag[r])){
            r=mid;
        }
        else l=mid;
    }
}