leetcode题目：搜索插入位置
输入: [1,3,5,6], 5
输出: 2
def searchInsert(self, nums: List[int], target: int) -> int:
last = len(nums) - 1
start = 0
while start <= last:
middle = (start + last) // 2
if nums[middle] > target:
last = middle - 1
elif nums[middle] < target:
start = middle + 1
else:
return middle
return start
