35. Search Insert Position

题目:

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.

Here are few examples.
[1,3,5,6], 5 → 2
[1,3,5,6], 2 → 1
[1,3,5,6], 7 → 4
[1,3,5,6], 0 → 0

代码如下：

class Solution {
public:
    int searchInsert(vector<int>& nums, int target) {
        int low = 0, high = nums.size() - 1;
        while (low <= high) {
          int mid = (low + high) / 2;
          if (nums[mid] < target) 
            low = mid + 1;
          else
            high = mid - 1;
        }
        return low;
    }
};

解题思路：

采用二分搜索，把问题分解为做多个子问题，速度更快。