原题
https://leetcode.com/problems/two-sum
题干
Given an array of integers, return indices of the two numbers such that they add up to a specific target.
You may assume that each input would have exactly one solution, and you may not use the same element twice.
Example:
Given nums = [2, 7, 11, 15], target = 9,
Because nums[0] nums[1] = 2 7 = 9, return [0, 1].
这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字数的这是占字
解
class Solution: def twoSum(self, nums, target): """ :type nums: List[int] :type target: int :rtype: List[int] """ for i in range(len(nums)): for j in range(i 1, len(nums)): if nums[i] nums[j] == target: return i,j解
class Solution: def twoSum(self, nums, target): """ :type nums: List[int] :type target: int :rtype: List[int] """ lookup = {} for i,num in enumerate(nums): if target - num in lookup: return lookup[target-num],i else: lookup[num] = i
