1. Two Sum
Description
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:1
2
3
4Given nums = [2, 7, 11, 15], target = 9,
Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1].
Idea
hashmap,一次遍历的时候,存之后可能出现的值和此时值的index,比如:[2, 7, 11, 15], t = 9, 遍历2的时候存k : 9 - 2 = 7 , v : 0
Code
1 | class Solution(object): |