Java 代码

import java.util.*;
public class Main{
    static int[] tmp;
    static long res = 0;
    public static void main(String[] args){
        Scanner sc=new Scanner(System.in);
        int n = sc.nextInt();
        int q = sc.nextInt();
        int[] nums = new int[n];
        for(int i = 0; i < n; i++){
            nums[i] = sc.nextInt();
        }
        for(int i = 0; i < q; i++){
            int k = sc.nextInt();
            int[] res = search(nums, k);
            System.out.println(res[0]+" "+res[1]);
        }
    }

    private static int[] search(int[] nums, int k){
        int l = 0;
        int r = nums.length-1;
        int[] res = new int[2];
        res[0] = -1;
        res[1] = -1;
        // find left pos
        while(l < r){
            int mid = l + (r-l)/2;
            if(nums[mid] < k){
                l = mid+1;
            }else{
                r = mid;
            }
        }

        if(nums[l] == k){
            res[0] = l;
        }


        // find right pos
        l = 0;
        r = nums.length-1;
        while(l < r){
            int mid = l+1 + (r-l)/2;
            if(nums[mid] > k){
                r = mid-1;
            }else{
                l = mid;
            }
        }

        if(nums[r] == k){
            res[1] = r;
        }

        return res;

    }

}