Given a target integer T and an integer array A sorted in ascending order, find the index i in A such that A[i] is closest to T.
Assumptions
- There can be duplicate elements in the array, and we can return any of the indices with same value.
Examples
- A = {1, 2, 3}, T = 2, return 1
- A = {1, 4, 6}, T = 3, return 1
- A = {1, 4, 6}, T = 5, return 1 or 2
- A = {1, 3, 3, 4}, T = 2, return 0 or 1 or 2
Corner Cases
- What if A is null or A is of zero length? We should return -1 in this case.
1 public int closest(int[] array, int target) {
2 // Write your solution here
3 if(array == null || array.length == 0) return -1 ;
4 int left = 0 , right = array.length -1 ;
5 while(left + 1< right){
6 int mid = left +(right - left )/2 ;
7 if(array[mid] == target) return mid ;
8 if(array[mid]<target){
9 left = mid ;
10 } else{
11 right = mid;
12 }
13 }
14 //post processing
15 if(Math.abs(array[left]-target)<= Math.abs(array[right] - target)){
16 return left ;
17 } else{
18 return right ;
19 }
20 }
