大佬们，问问这个代码为什么第一个测试点wa了，最后一个测试点TLE了

using namespace std;

const int N = 1e6+10;

typedef pair<int,int> PII;

long long a[N];
long long n,m;

long long sweet(long long x)
{
	long long l = 1,r=n;
	while(l <= r)
	{
		long long mid=l+(r-l)/2;
		if( a[mid] < x ) l=mid+1;
		else if(a[mid] > x ) r=mid-1;
		else if(a[mid] == x)
		{
			while(a[mid]==a[mid-1] && a[mid-1] == x) mid--;
			return mid;
		}
    }
    if(a[l] == 1) return 1;
    return -1;
}

int main()
{
	scanf("%lld %lld",&n,&m);
	for(int i = 1;i <= n; i++ ) scanf("%lld",&a[i]);
	while(m--)
	{
		long long x;
		scanf("%lld",&x);
		printf("%lld ",sweet(x));		
	}
	return 0;
}