【Leetcode】【python】Search Insert Position 搜索插入位置

题目大意

查找目标数字在排序数组的位置，若没有该数字，则返回应该插入他的位置，假设没有重复数字

解题思路

二分查找的变种

代码

left <= right

class Solution {
    public int searchInsert(int[] nums, int target) {
        int low = 0;
        int high = nums.length-1;
        int mid = 0;
        while (low <= high) {
            mid = low + (high - low) * 1/2;
            if(nums[mid] == target) {
                return mid;
            }
            if(nums[mid] > target) {
                high = mid - 1;
            }
            else {
                low = mid + 1;
            }
        }
        return low; //return low 应该插入的位置
    }
}

left < right

class Solution(object):
    def searchInsert(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: int
        """
        if not nums:
            return 0
        left = 0
        right = len(nums) - 1
        while left < right:
            print left, right
            mid = (left + right) / 2
            if nums[mid] < target:
                left = mid + 1
            elif nums[mid] > target:
                right = mid - 1
            else:
                return mid
        if nums[left] < target:
            return left + 1
        else:
            return left

总结

关于二分查找的细节，直接看查找的博客