Problem

Given an array of integers, returnindicesof the two numbers such that they add up to a specific target.

You may assume that each input would haveexactlyone solution, and you may not use thesameelement twice.

Example:

Given nums = [2, 7, 11, 15], target = 9,

Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1].

Solutions

Two Sum相关的问题的两种做法

• Hash Map

• Sort + Two Pointers