Search Insert Position

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

我比较笨的就从头到尾依次的比较，发现这并不是一个很好的办法，虽然可以完成要求，但是所花费的时间很多。
看到好的方法是用二分查找来解决这个问题。

class Solution(object):    def searchInsert(self, nums, target):        """        :type nums: List[int]        :type target: int        :rtype: int        """        if target < nums[0]:            return 0        elif target > nums[-1]:            return len(nums)        l, r = 0, len(nums) - 1        while l <= r:            m = (l + r)/2            if nums[m] == target:                return m            elif nums[m] > target:                if nums[m-1] < target:                    return m                else:                    r = m -1            elif nums[m] < target:                if nums[m+1] > target:                    return m+1                else:                    l = m + 1