LeetCode in Python-1. Two Sum 两数之和

Leetcode LeetCode

创建时间:2019-07-26 16:57

字数:188 阅读:

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题目描述
解法1、切片后查找
解法2、hash字典
解法3、同2
出处

题目描述
解法1、切片后查找
解法2、hash字典
解法3、同2
出处

题目描述

两数之和

解法1、切片后查找

class Solution:
    def twoSum(self, nums: List[int], target: int) -> List[int]:
        for i in nums:
            j = target - i
            start_index = nums.index(i)
            next_index = start_index + 1
            temp_nums = nums[next_index:]
            if j in temp_nums:
                return [nums.index(i), next_index + temp_nums.index(j)]

注意返回值index的转换

解法2、hash字典

class Solution:
    def twoSum(self, nums: List[int], target: int) -> List[int]:
        dict = {}
        for i in range(len(nums)):
            if target - nums[i] not in dict:
                dict[nums[i]] = i
            else:
                return [dict[target-nums[i]], i]

解法3、同2

class Solution:
    def twoSum(self, nums: List[int], target: int) -> List[int]:
        dict = {}
        for i, num in enumerate(nums):
            if target - num in dict:
                return [dict[target-num], i]
            dict[num] = i

借助枚举函数，方法同2