fork download 
  1. import java.util.*;
  2.  
  3. public class Main {
  4.     public static void main(String[] args) {
  5.         int[] arr = {1, 2, 2, 7, 8, 8, 8, 8, 9, 10};
  6.         int k = 8;
  7.         int firstIndex = findIndex(arr, k, true);
  8.         int lastIndex = findIndex(arr, k, false);
  9.         System.out.println(firstIndex + " " + lastIndex);
  10.     }
  11.  
  12.     public static int findIndex(int[] arr, int k, boolean findFirst) {
  13.         int left = 0, right = arr.length - 1, result = -1;
  14.  
  15.         while (left <= right) {
  16.             int mid = left + (right - left) / 2;
  17.  
  18.             if (arr[mid] == k) {
  19.                 result = mid;
  20.                 if (findFirst) {
  21.                     right = mid - 1;
  22.                 } else {
  23.                     left = mid + 1;
  24.                 }
  25.             } else if (arr[mid] < k) {
  26.                 left = mid + 1;
  27.             } else {
  28.                 right = mid - 1;
  29.             }
  30.         }
  31.  
  32.         return result;
  33.     }
  34. }
  35.  
Success #stdin #stdout 0.13s 55440KB
comments (?)
stdin 
Standard input is empty
stdout 
4 7
https://ideone.com/JwxAfx
language:
Java (HotSpot 12)
created:
282 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!