1、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].

python 代码段

class Solution(object):
    def twoSum(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: List[int]
        """
        for index1 in range(len(nums)):
            for index2 in range(index1,len(nums)):
                if index1 == index2:
                    continue
                if nums[index1]+nums[index2]==target:
                    return [index1,index2]