LeetCode 第一题two sum （python）

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].

第一种简单解法：

nums = [2, 7,  5, 6,11]
target = 9
for i in range(len(nums)):
    for j in range(i + 1 , len(nums)):
        if target - nums[i] == nums[j]:
            print(i, j)

第二种解法：

nums = [2, 7,  5, 6, 11]
target = 9
d = nums[:]
i = 0
while i < len(nums):
    if target - nums[i] in d:
        if d.index(target - nums[i]) > i:
            print(i, d.index(target - nums[i]))
        # else:
        #     pass
    else:
        pass
    i += 1