代码如下

#include<bits/stdc++.h>
using namespace std;

const long long N=100000010;
int n,m;
int q[N];

int main ()
{
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++)scanf("%d",&q[i]);
	while(m--)
	{
		int x;
		scanf("%d",&x);
		int l=0,r=n-1;
		while (l < r)
   		{
        	int mid = (l + r)/2;
        	if (q[mid]>=x) r = mid;
        	else l = mid + 1;
   		}
   		if(q[l]!=x)cout<<"-1"<<endl;
   		else
   		{
   			cout<<l<<" ";
   			int l=0,r=n-1;
   			while (l < r)
   			{
        		int mid = l + r + 1 >> 1;
        		if (q[mid]<=x) l = mid;
        		else r = mid - 1;
   			}
   		//	cout<<l<<endl; 
		}

	}
	
	return 0;
}