class Solution(object):
    def twoSum(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: List[int]
        """
        num_list = []

        for i in range(len(nums)):
            for j in nums:
                if nums[i] + j == target and i != nums.index(j):
                if len(num_list) < 2:
                    num_list.append(nums[i])
                    num_list.append(j)

        index = 0
        nums_ind = []
        for j in nums:
            if nums[index] in num_list:
                nums_ind.append(index)
            index+=1

        return nums_ind

之後可以試著少用迴圈

試想:

利用 n = target – num 的方法

例如:

[2,7,11,15],   9 – 2 = 7, 找7

[3,2,4], 6 – 2 = 4, 找4