leetcode 1. Two Sum
LeetCode sum two
2023-09-14 09:11:52 时间
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].
class Solution:
def twoSum(self, nums, target):
"""
:type nums: List[int]
:type target: int
:rtype: List[int]
"""
m = {}
for i,n in enumerate(nums):
if target-n in m:
return [m[target-n], i]
m[n] = i
另外就是sort后的解法：
class Solution:
def twoSum(self, nums, target):
"""
:type nums: List[int]
:type target: int
:rtype: List[int]
"""
nums2 = [(i,n) for i,n in enumerate(nums)]
nums2.sort(key=lambda x: x[1])
i,j = 0, len(nums2)-1
while i<j:
if nums2[i][1] + nums2[j][1] == target:
return [nums2[i][0], nums2[j][0]]
elif nums2[i][1] + nums2[j][1] > target:
j -= 1
else:
i += 1
如果是二分查找的two sum，我就不写了。