AdventOfCode/day22.js

'use strict';

var bossStats = {
	hp: 71,
	damageAmt: 10,
}

class Player {
	constructor(initial, isWizard) {
		this.history = [];
		this.initial = initial;
		this.isWizard = !!isWizard;

		if (this.isWizard) {
			this.spells = [
				{
					cost: 53,
					effect: (m, o) => o.damage(4),
				},
				{
					cost: 73,
					effect: (m, o) => { o.damage(2); m.hp += 2; },
				},
				{
					cost: 113,
					start: (m, o) => m.armor += 7,
					effect: (m, o) => { },
					end: (m, o) => m.armor -= 7,
					duration: 6,
				},
				{
					cost: 173,
					effect: (m, o) => o.damage(3),
					duration: 6,
				},
				{
					cost: 229,
					effect: (m, o) => m.mana += 101,
					duration: 5,
				},
			];
		}

		this.start();
	}

	attack(opponent, spellIdx) {
		if (!this.isWizard) {
			opponent.damage(this.damageAmt);
		} else {
			this.history.push(spellIdx);
			var spell = this.spells[spellIdx];
			this.spent += spell.cost;
			this.mana -= spell.cost;

			if (spell.duration) {
				var newSpell = {
					idx: spellIdx,
					effect: spell.effect,
					duration: spell.duration,
				};
				if (spell.start) {
					spell.start(this, opponent);
				}
				if (spell.end) {
					newSpell.end = spell.end;
				}
				this.activeSpells.push(newSpell);
			} else {
				spell.effect(this, opponent);
			}
		}
	}

	damage(n) {
		this.hp -= Math.max(1, n - this.armor);
	}

	duplicate() {
		var newPlayer = new Player(this.initial, this.isWizard);
		newPlayer.hp = this.hp;
		newPlayer.spent = this.spent;
		newPlayer.armor = this.armor;
		newPlayer.turn = this.turn;
		for (var i = 0; i < this.activeSpells.length; i++) {
			newPlayer.activeSpells.push(Object.assign({}, this.activeSpells[i]));
		}
		for (var i = 0; i < this.history.length; i++) {
			newPlayer.history.push(this.history[i]);
		}

		if (this.isWizard)
			newPlayer.mana = this.mana;
		else
			newPlayer.damageAmt = this.damageAmt;

		return newPlayer;
	}

	takeTurn(opponent) {
		this.turn++;

		for (var i = 0; i < this.activeSpells.length; i++) {
			var spell = this.activeSpells[i];

			if (spell.duration > 0) {
				spell.effect(this, opponent);
				spell.duration--;

				if (spell.duration === 0 && spell.end) {
					spell.end(this, opponent);
				}
			}
		}
	}

	start() {
		this.hp = this.initial.hp;
		this.spent = 0;
		this.armor = 0;
		this.turn = 0;
		this.activeSpells = [];
		if (this.isWizard)
			this.mana = this.initial.mana;
		else
			this.damageAmt = this.initial.damageAmt;
	}
}


var me = new Player({ hp: 50, mana: 500 }, true);
var boss = new Player(bossStats);

var cheapestSpent = Infinity;

function playAllGames(me, boss, partTwo, depth) {
	depth = depth || 0;
	for (var i = 0; i < me.spells.length; i++) {
		var spellMatch = false;
		for (var j = 0; j < me.activeSpells.length; j++) {
			if (me.activeSpells[j].duration > 1 && i === me.activeSpells[j].idx) {
				spellMatch = true;;
			}
		}
		if (spellMatch)
			continue;
		if (me.spells[i].cost > me.mana) {
			continue;
		}

		var newMe = me.duplicate();
		var newBoss = boss.duplicate();

		if (partTwo)
			newMe.hp--;

		newMe.takeTurn(newBoss);
		newBoss.takeTurn(newMe);
		newMe.attack(newBoss, i);

		newMe.takeTurn(newBoss);
		newBoss.takeTurn(newMe);
		newBoss.attack(newMe);


		if (newBoss.hp <= 0) {
			cheapestSpent = Math.min(cheapestSpent, newMe.spent);
		}

		if (newMe.hp > (partTwo ? 1 : 0) && newBoss.hp > 0 && newMe.spent < cheapestSpent)
			playAllGames(newMe, newBoss, partTwo, depth + 1);
	}
}

playAllGames(me, boss);
console.log('Part One:', cheapestSpent);
cheapestSpent = Infinity;
playAllGames(me, boss, true);
console.log('Part Two:', cheapestSpent);