18-4Sum
Sat 17 May 2025
https://leetcode.com/problems/4sum
import pyutil as pyu
pyu.get_local_pyinfo()
print(pyu.ps2("python-dotenv"))
from typing import List
class Solution:
def fourSum(self, nums: List[int], target: int):
ans = []
def nSum(l: int, r: int, target: int, n: int, path: List[int], ans: List[List[int]]) -> None:
if r - l + 1 < n or n < 2 or target < nums[l] * n or target > nums[r] * n:
return
if n == 2:
while l < r:
summ = nums[l] + nums[r]
if summ == target:
ans.append(path + [nums[l], nums[r]])
l += 1
while nums[l] == nums[l - 1] and l < r:
l += 1
elif summ < target:
l += 1
else:
r -= 1
return
for i in range(l, r + 1):
if i > l and nums[i] == nums[i - 1]:
continue
nSum(i + 1, r, target - nums[i], n - 1, path + [nums[i]], ans)
nums.sort()
nSum(0, len(nums) - 1, target, 4, [], ans)
return ans
new Solution().fourSum()
Score: 5
Category: leetcode