背模板

C++ 代码

#include<iostream>
using namespace std;
const int N = 1e6 + 10;
int q[N];
int main()
{
    int n, m;
    cin >> n >> m;
    for(int i = 0; i < n; i++)  cin >> q[i];
    while(m--)
    {
        int x;
        cin >> x;
        int l = 0, r = n - 1;
        while(l < r)
        {
            int mid = l + r >> 1;
            if(q[mid] >= x) r = mid;
            else    l = mid + 1;
        }
        if(q[l] != x) cout << "-1 -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;
        }
    }
}

Java 代码

import java.util.Scanner;
public class Main
{
    static final int N = 1000010;
    static final int q[] = new int[N];
    public static void main(String[] args)
    {
        Scanner get = new Scanner(System.in);
        int n = get.nextInt();
        int m = get.nextInt();
        for(int i = 0; i < n; i++)
            q[i] = get.nextInt();
        while(m > 0)
        {
            int x = get.nextInt();
            int l = 0, r = n - 1;
            while(l < r)
            {
                int mid = l + r >> 1;
                if(q[mid] >= x) r = mid;
                else    l = mid + 1;
            }
            if(q[l] != x)   System.out.println("-1 -1");
            else
            {
                System.out.print(l + " ");
                l = 0;
                r = n - 1;
                while(l < r)
                {
                    int mid = l + r + 1 >> 1;
                    if(q[mid] <= x) l = mid;
                    else    r = mid - 1;
                }
                System.out.println(l);
            }
            m--;
        }
    }
}