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Algorithms & data structures

Classic patterns — search, sort, stacks, queues, and practical complexity-aware code.

3 matches
Algorithms & data structures medium

Find All Triplets with Sum Zero in Python

This code finds all unique triplets in an array that sum to zero using a sorted array and two-pointer technique.

triplets two-pointers sorting
Python
def find_triplets(nums):
    nums.sort()
    n = len(nums)
    triplets = []
    for i in range(n - 2):
        if i > 0 and nums[i] == nums[i - 1]:
            continue
        left, right = i + 1, n - 1
        while left < right:
            total = nums[i] + nums[left] + nums[right]
            if total == 0:
    …
15 0 Open
Algorithms & data structures medium

How to Find Four Sum Quadruplets in Python (Sorted Demo)

Find all unique quadruplets in a sorted array that sum to a target, with duplicate skipping.

two-pointers sorting four-sum
Python
def four_sum(nums, target):
    nums.sort()
    result = []
    n = len(nums)

    for i in range(n - 3):
        if i > 0 and nums[i] == nums[i - 1]:
            continue
        for j in range(i + 1, n - 2):
            if j > i + 1 and nums[j] == nums[j - 1]:
                continue
            left, right = j + 1…
13 0 Open
Algorithms & data structures medium

Split Array Largest Sum in Python (Minimize Largest Subarray Sum)

Binary search + greedy check to split an array into k subarrays while minimizing the largest subarray sum.

binary-search greedy array
Python
def can_split(nums, k, max_sum):
    subarrays = 1
    current_sum = 0
    for num in nums:
        if current_sum + num <= max_sum:
            current_sum += num
        else:
            subarrays += 1
            current_sum = num
            if subarrays > k:
                return False
    return True

def spli…
15 0 Open

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