对左右边界查找的函数封装

把函数封装 方便使用 :)

import java.util.*;
import java.io.*;

public class Main{

    private static final int N = 1000010;
    private static final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    private static final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

    public static void main(String[] args) throws IOException{
        String[] strs = br.readLine().split(" ");
        int n = Integer.parseInt(strs[0]);
        int q = Integer.parseInt(strs[1]);
        strs = br.readLine().split(" ");
        int[] arr = new int[N];
        for(int i = 0; i < n ;++i){
            arr[i] = Integer.parseInt(strs[i]);
        }
        int tar,left;
        while(q-- != 0){
            strs = br.readLine().split(" ");
            tar = Integer.parseInt(strs[0]);
            left = getLeftBoundary(arr,tar,n);
            System.out.println(left+" "+(left == -1 ? -1 : getRightBoundary(arr,tar,n)));
        }
    }

    // 查找一个数字在数组中的左边界索引
    public static int getLeftBoundary(int[] arr,int target,int n){
        int mid,l = 0,r = n - 1;
        while(l < r){
            mid = (l + r) >> 1;
            if(arr[mid] < target) l = mid + 1;
            else r = mid;
        }
        return arr[l] != target ? -1 : l;
    }

    // 查找一个数字在数组中的右边界索引
    public static int getRightBoundary(int[] arr,int target,int n){
        int mid,l = 0, r = n - 1;
        while(l < r){
            mid = l + r + 1 >> 1;
            if(arr[mid] > target) r = mid - 1;
            else l = mid;
        }
        return arr[l] != target ? -1 : l;
    }
}