Search Insert Position

Problem Description

Given a sorted array of distinct integers and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.

You must write an algorithm with O(log n) runtime complexity.

Example 1:

Input: nums = [1,3,5,6], target = 5
Output: 2

Example 2:

Input: nums = [1,3,5,6], target = 2
Output: 1

Example 3:

Input: nums = [1,3,5,6], target = 7
Output: 4

Constraints:

• 1 <= nums.length <= 104
• -104 <= nums[i] <= 104
• nums contains distinct values sorted in ascending order.
• -104 <= target <= 104

Solution (JavaScript)

/**
 * @param {number[]} nums
 * @param {number} target
 * @return {number}
 */
var searchInsert = function(nums, target) {
    let left = 0, right = nums.length - 1;
    
    while(left <= right) {
        const mid = Math.floor((left + right)/2);
        if(nums[mid] === target) {
            return mid;
        } else if (nums[mid] > target && (mid === 0 || nums[mid-1]<target)) {
            return mid;
        } else if (nums[mid] < target && (mid === nums.length-1 || nums[mid+1]>target)) {
            return mid+1;
        } else if (nums[mid] > target) {
            right = mid-1;
        } else if (nums[mid] < target) {
            left = mid+1;
        }
    }
};