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].Java实现：
public class Solution { public int[] twoSum(int[] nums, int target) { HashMap<Integer,Integer> map=new HashMap<Integer,Integer>(); int result[]=new int[2]; for(int i=0;i<nums.length;i++){ int num=target-nums[i]; if(map.containsKey(num)){ result[0]=map.get(num); result[1]=i; return result; } map.put(nums[i],i); } return result; } }PHP实现：
<?php function twoSum($nums,$target){ $result=array(); foreach ($nums as $key=>$value){ $num=$target-$nums[$key]; if ($i=array_search($num,$nums)){ $result[0]=$key; $result[1]=$i; return $result; } } } print_r(twoSum(array(7,3,4,7),7));