35. Search Insert Position

LeetCode 
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class Solution {
    public int searchInsert(int[] nums, int target) {
        int n = nums.length;
        int left = 0;
        int right = n - 1;
        while (left <= right) {
            int mid = left + (right - left) / 2;
            if (nums[mid] == target) {
                return mid;
            } else if (nums[mid] < target) {
                left = mid + 1;
            } else {
                right = mid - 1;
            }
        }
        return left;
    }
}

Remarks:

  1. TC: $O(\log n)$
  2. In a standard binary search senario, left is always the first index that is >=target; right is at the last index that is <target. Why? because the while condition is left <= right, and the loop ends when left > right.