everyutil/array/arrayLongestIncreasingSubsequence.js

A comprehensive library of lightweight, reusable utility functions for JavaScript and TypeScript, designed to streamline common programming tasks such as string manipulation, array processing, date handling, and more.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.arrayLongestIncreasingSubsequence = void 0;
/**
 * Returns the longest increasing subsequence in the array.
 * @author @dailker
 * @param {number[]} array - Input array.
 * @returns {number[]} Longest increasing subsequence.
 */
function arrayLongestIncreasingSubsequence(array) {
    const n = array.length;
    if (n === 0)
        return [];
    const dp = Array(n).fill(1);
    const prev = Array(n).fill(-1);
    let maxLen = 1, maxIdx = 0;
    for (let i = 1; i < n; i++) {
        for (let j = 0; j < i; j++) {
            if (array[i] > array[j] && dp[j] + 1 > dp[i]) {
                dp[i] = dp[j] + 1;
                prev[i] = j;
            }
        }
        if (dp[i] > maxLen) {
            maxLen = dp[i];
            maxIdx = i;
        }
    }
    const result = [];
    for (let i = maxIdx; i !== -1; i = prev[i]) {
        result.push(array[i]);
    }
    return result.reverse();
}
exports.arrayLongestIncreasingSubsequence = arrayLongestIncreasingSubsequence;