题目：给定一个数字列表nums，找出其中和为特定值target的两个数，返回其下标。
解法一：最常规的两个for循环嵌套
def twoSum(nums, target):
for i in range(len(nums)):
for j in range(i + 1, len(nums)):
if nums[i] + nums[j] == target:
return i, j
else:
j = j + 1
i = i + 1
解法二：
def twoSum_simple(nums, target):
for i, num in enumerate(nums):
sub_num = target - num
if sub_num in nums:
t_index = nums.index(sub_num)
if t_index != i:
return [i, t_index]
