C++ 代码

#include <iostream>
using namespace std;

const int N = 1e6+10;
int q[N];

int lower_bound(int a[],int left,int right,int x)
{
    int mid;
    while(left < right)
    {
        mid = left+right >> 1;
        if(a[mid] >= x) right = mid;
        else left = mid+1;
    }
    return left;
}
int upper_bound(int a[],int left,int right,int x)
{
    int mid;
    while(left < right)
    {
        mid = left + right >> 1;
        if(a[mid] > x)  right = mid;
        else left = mid + 1;
    }
    return left-1;
}
int main()
{
    int n,x,que,LB,RB;
    cin >> n >>x;
    for(int i=0;i<n;i++)
        cin >> q[i];

    while(x--)
    {   
        cin >> que;
        LB = lower_bound(q,0,n,que);
        RB = upper_bound(q,0,n,que);
        if(q[LB] != que)  LB = -1;
        if(q[RB] != que )  RB = -1;
        cout << LB << ' '<< RB << endl;
    }

    return 0;
}