Leetcode no. 34

34. Search for a Range

 

Given a sorted array of integers, find the starting and ending position of a given target value.

Your algorithm's runtime complexity must be in the order of O(log n).

If the target is not found in the array, return [-1, -1].

For example,
Given [5, 7, 7, 8, 8, 10] and target value 8,
return [3, 4].

public class Solution {    public int[] searchRange(int[] nums, int target) {        int[] res= {-1, -1};        if (nums.length==0 || nums[0]>target || nums[nums.length-1]<target) return res;        int left=0, right= nums.length-1;        while (left<right){            int center= (left+right)/2;            if (nums[center]<target) left= center+1;            else right= center;        }        if (nums[left]!=target) return res;        else res[0]=left;        right= nums.length-1;        while (left<right){            int center= (left+right)/2+1;            if (nums[center]>target) right= center-1;            else left= center;        }        res[1]= left;        return res;    }}