LeetCode: Two sum: Given an array of integers, return indices of the two numbers such that they add up to a specific target.

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

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

class Solution(object):
    def twoSum(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: List[int]
        """
        arrH = {}
        for i in xrange(len(nums)):
            arrH[nums[i]] = i
            
        for j in xrange(len(nums)):
            diff = target - nums[j]
            print 'diff: ', diff
            if diff in arrH and j != arrH[diff]:
                print j, arrH[diff]
                return [j, arrH[diff]]