Egg Dropping by Number of Moves in JavaScript

"use strict";
// Egg Dropping by Number of Moves in JavaScript
//
// PURPOSE
// Instead of trying every floor, this DP counts how many floors can be distinguished with a
// given number of moves and eggs.
//
// METHOD
// For each move, update egg counts downward using
// reachable[e]=reachable[e]+reachable[e-1]+1. Stop when the available egg count covers all
// floors.
//
// COMPLEXITY
// O(eggs * moves) time and O(eggs) space, where moves is the answer.
//
// CONTRACT
// 1<=eggs<=30, 0<=floors<=1000000. Returns the minimum worst-case number of drops.
// Reachability is capped at floors to avoid unnecessary growth.
// Public APIs infer array lengths except in C, which accepts pointer/length pairs. Vertex
// counts and matrix dimensions remain explicit. Arrays must contain signed 32-bit integers.
// Sorted order, correct tree topology, and caller-owned data-structure invariants are
// preconditions; checking them on every query would change query complexity.
// Scalar and shape checks are included. Value-range checks are included where needed to
// prevent invalid indexing or nontermination. Allocation sizes are capped at 4,000,000
// workspace entries. Arithmetic outside Python raises an error on 32-bit overflow; Python
// uses arbitrary precision. Native allocation failures propagate. In-place outputs may be
// partly updated after arithmetic failure. These are single-threaded, in-memory
// implementations.
//
// LANGUAGE DETAILS
// Node.js 18+: Int32Array inputs and workspaces provide compact integer storage. Automatic
// lengths and checked arithmetic reject values outside signed 32-bit. Invalid inputs or
// overflow throw RangeError.
//
// EXAMPLE
// Expected return: 14.
// Run: node example.js
// Tests for this exact source artifact run before publication. The accompanying source
// archive includes unit cases, runtime results, and source hashes.

function alg_require(valid) { if (!valid) throw new RangeError("invalid algorithm input"); }
function alg_checked(v) { if (!Number.isInteger(v) || v < -2147483648 || v > 2147483647) throw new RangeError("32-bit result overflow"); return v; }
function alg_add(a,b) { return alg_checked(a+b); }
function alg_sub(a,b) { return alg_checked(a-b); }
function alg_mul(a,b) { return alg_checked(a*b); }
function alg_size(n) { alg_require(Number.isInteger(n) && n>=0 && n<=4000000); return n; }

function egg_drop(eggs, floors) {
    alg_require(Number.isInteger(eggs) && eggs >= -2147483648 && eggs <= 2147483647);
    alg_require(Number.isInteger(floors) && floors >= -2147483648 && floors <= 2147483647);
    alg_require(((eggs >= 1) && (eggs <= 30) && (floors >= 0) && (floors <= 1000000)));
    let reachable = new Int32Array(alg_size(alg_add(eggs, 1)));
    let moves = 0;
    let e = 0;
    while ((reachable[eggs] < floors)) {
        moves = alg_add(moves, 1);
        e = eggs;
        while ((e > 0)) {
            reachable[e] = Math.min(floors, alg_add(alg_add(reachable[e], reachable[alg_sub(e, 1)]), 1));
            e = alg_sub(e, 1);
        }
    }
    return moves;
}

let eggs = 2;
let floors = 100;
let result = egg_drop(eggs, floors);
console.log(result);