问题描述
Given a sorted array 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 may assume no duplicates in the array.
Example

Input: [1,3,5,6], 5
Output: 2
Input: [1,3,5,6], 7
Output: 4
Input: [1,3,5,6], 0
Output: 0

思路1：直接查找

/**
 * @param {number[]} nums
 * @param {number} target
 * @return {number}
 */
var searchInsert = function(nums, target) {
    for(let i=0;i<nums.length;i++){
        if(nums[i]>=target){
            return i;
        }     
    }  
    if(nums[nums.length-1]<target){
        return nums.length;
    }
};

思路2：二分查找

var searchInsert = function(nums, target) {
    var low = 0;
    var high = nums.length - 1;
    while (low <= high) {
        var mid = Math.floor((low + high) / 2);
        if(nums[mid] < target) {
            low = mid + 1;
        }
        else if(nums[mid] > target){
            high = mid - 1;
        }
        else {
            return mid;
        }
    }
    return high + 1;
};