#include <bits/stdc++.h> using namespace std; const int N = 1e6 + 10; int n, a[N], m; int x;

int main() { scanf("%d %d", &n, &m); for (int i = 1; i <= n; i++) scanf("%d", &a[i]); while (m--) { // O(m*logn) scanf("%d", &x); // 二分 int l = 1, r = n; int ans = -1; //不重复的里面查找数字出现的位置 while (l <= r) { // O(logn) int mid = (l + r) / 2; if (a[mid] == x) { ans = mid ; break; } else if (a[mid] < x) { l = mid + 1; } else r = mid - 1; } printf("%d\n", ans); } return 0; }

#include <bits/stdc++.h>
using namespace std;
const int N=1e6+10;
int a[N];
int n,m;
int x;

int main(){
	scanf("%d %d",&n,&m);
	for(int i=1;i<=n;i++)
		scanf("%d",&a[i]);
	while(m--){
		scanf("%d",&x);
		int l=1,r=n;
		int ans=-1;
		while(l<=r){
			int mid=(l+r)/2;
			if(a[mid]==x){
				ans=mid;
				break;
			}else if(a[mid]<x){
				l=mid+1;
			}else 
				r=mid-1;
		}
		printf("%d\n",ans);
	}
	return 0;
}