find questions

`Array.prototype.find` returns the first element in the array that satisfies the provided testing function. If no elements satisfy the function, it returns `undefined`. It does not modify the original array. 

const arr = [1, 2, 3];
const firstEven = arr.find(num => num % 2 === 0);
console.log(firstEven); // 2

`Array.prototype.findIndex` returns the index of the first element in the array that satisfies the provided testing function. If no elements satisfy the function, it returns `-1`. It does not modify the original array. 

const arr = [5, 12, 8];
const index = arr.findIndex(num => num > 10);
console.log(index); // 1

Use Kadane's Algorithm to find the maximum sum. Initialize the maximum sum and current sum as the first element, then iterate through the array updating these values. For example, for [1, -2, 3, 4, -1], the maximum subarray sum is 7.

Use a sliding window and hash maps to compare character counts. Slide the window across the string and check if the counts match. For example, in 'cbaebabacd' with pattern 'abc', the start indices of anagrams are 0 and 6.

Use a dynamic programming approach to build a table that tracks palindromic substrings. For example, in 'babad', the longest palindromic substring is 'bab' or 'aba'.

Use a min-heap of size K to keep track of the K largest elements. For each element, if it is larger than the smallest element in the heap, replace the smallest. For example, in [3, 2, 1, 5, 6, 4], the 2nd largest element is 5.

Use BFS to explore the shortest path in an unweighted graph. Enqueue the starting node, then visit each neighbor while updating distances. For example, in a graph with edges (1 -> 2), (2 -> 3), (1 -> 3), the shortest path from 1 to 3 is 1 -> 3.

Use topological sorting to order nodes and then apply dynamic programming to find the longest path. For example, in a DAG with edges 1 -> 2, 1 -> 3, 2 -> 4, 3 -> 4, the longest path is 1 -> 2 -> 4 or 1 -> 3 -> 4.

Use two pointers to traverse the linked lists. When one pointer reaches the end, move it to the start of the other list. Continue until both pointers meet. For example, if lists intersect at node with value 8, both pointers will eventually reach this node.