java 代码

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
    static final int N = 100010;
    static int[] a = new int[N];

    public static void main(String[] args) throws IOException {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        String[] s1 = in.readLine().split(" ");
        int n = Integer.parseInt(s1[0]);//数组长度为n
        int q = Integer.parseInt(s1[1]);//q次查询
        String[] s2 = in.readLine().split(" ");
        for(int i = 0; i < n; i ++) a[i] = Integer.parseInt(s2[i]);

        while(q -- > 0) {
            int k = Integer.parseInt(in.readLine());

            //二分查找
            int l = 0, r = n - 1;
            while(l < r) {
                int mid = l + r >> 1;
                if(a[mid] >= k) r = mid;
                else l = mid + 1;
            }
            if(a[l] != k) System.out.println("-1 -1");
            else {
                int left = l;
                l = 0;
                r = n - 1;
                while(l < r) {
                    int mid = l + r + 1 >> 1;
                    if(a[mid] <= k) l = mid;
                    else r = mid -1;
                }
                System.out.println(left + " " + l);
            }
        }
    }
}