Leetcode——两数之和（twoSum）、三数之和（threeSum）——Python

一、两数之和

class Solution(object):
    def twoSum(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: List[int]
        """
        #对应每个测试案例，输出两个数，小的先输出。
        # ls = []
        # if not isinstance(nums, list):
        #     return ls
        # for i, v in enumerate(nums):
        #     for v1 in nums[i:]:
        #         if (v + v1) == target:
        #             ls.append([v,v1])
        # if ls:
        #     return ls[0]
        # else:
        #     return ls
         
        keys={}
        for i in xrange(len(nums)):
            if target-nums[i] in keys:
                return [keys[target-nums[i]],i]
            if nums[i] not in keys:
                keys[nums[i]]=i
class Solution(object):
    def