#arrays code explainers

java

public List<int[]> merge(int[][] intervals) {
    if (intervals.length == 0) {
        return new ArrayList<>();
    }

Merging overlapping intervals in Java

intervals sorting greedy

Intermediate 7 steps

php

function deepMerge(array $defaults, array $overrides): array
{
    foreach ($overrides as $key => $value) {
        if (

Recursively merging nested config arrays in PHP

recursion arrays configuration

Intermediate 6 steps

java

public class SortedListMerger {
 
    public static int[] merge(int[] a, int[] b) {
        int[] result = new int[a.length + b.length];

Merging two sorted arrays in Java

two-pointers merging arrays

Beginner 6 steps

javascript

// Sliding window maximum using a monotonic decreasing deque.
// Returns an array of the maximum value within each window of size k.
function maxSlidingWindow(nums, k) {
  const result = [];

Sliding window maximum with a deque

sliding-window monotonic-deque amortized-analysis

Advanced 7 steps

java

import java.util.Arrays;
 
public class SlidingWindow {
    // Returns the maximum sum of any contiguous subarray of length k.

The sliding window technique in Java

sliding-window arrays algorithms

Intermediate 8 steps

python

def two_sum_sorted(numbers, target):
    """Find indices of two values that sum to target in a sorted array."""
    left, right = 0, len(numbers) - 1
    while left < right:

Two-pointer search on sorted arrays

two-pointers arrays sorting

Intermediate 9 steps

javascript

function flatten(arr) {
  const result = [];
  for (const item of arr) {
    if (Array.isArray(item)) {

Flattening nested arrays with recursion

recursion arrays reduce

Intermediate 7 steps