v1.0
def twoSum(nums,target):
lens = len(nums)
for i in range(lens):
for j in range(i+1,lens):
if nums[i]+nums[j]==target:
return i,j遍历可通过时间过长
v2.0
def twoSum(nums,target):
lens = len(nums)
for i in range(lens):
one = nums[i]
two = target - nums[i]
if two in nums:
j = nums.index(two)
if i!=j:
return i,j一次循环寻找确认是否存在另一个值
v3.0
def twoSum(nums,target):
lens = len(nums)
dic = {}
for i in range(lens):
two = target - nums[i]
if nums[i] in dic:
return dic[nums[i]],i
else :
dic[two]=i将可能需要求得的值存到字典里，如果出现目标结果，输出返回值