class Solution(object):
def twoSum(self, nums, target):
"""
:type nums: List[int]
:type target: int
:rtype: List[int]
"""
# Create a record dict : Num |-> Index
self.recd_dict = {}
for i in range(len(nums)):
# For each index in nums
curNum = nums[i]
if self.recd_dict.has_key(target - curNum):
# If dict has target, then return the index
return [self.recd_dict[target - curNum], i]
else:
# else put current number and the index in to the dict.
self.recd_dict[curNum] = i
https://leetcode.com/problems/two-sum/
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].