35.搜索插入位置

使用二分查找：

class Solution {
    public int searchInsert(int[] nums, int target) {
        int low = 0,high = nums.length -1;
        while(low <= high){
            //注意每次循环完都要计算mid
            int mid = (low + high)/2;
            if(nums[mid] == target){
                return mid;
            }
            if(nums[mid] < target){
                low = mid + 1;
            }
            if(nums[mid] > target){
                high = mid -1;
            }
        }
        return low ;
    }
}