1. Two Sum Java Solutions

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.

Example:

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

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

UPDATE (2016/2/13):
The return format had been changed to zero-based indices. Please read the above updated description carefully.

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public class Solution {
    public int[] twoSum(int[] nums, int target) {
        Map<Integer, Integer> map = new HashMap<Integer, Integer>();
        int[] res = new int[2];
        for(int i =0;i<nums.length;i++){
            if(map.containsKey(target - nums[i])){
                res[0] = map.get(target - nums[i]);
                res[1] = i;
            }
            map.put(nums[i],i);
        }
        return res;
    }
}