day 22 problems

aoc/puzzles/2015/day22/solution.js

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+/**
+ * aoc/puzzles/2015/day22/solution.js
+ * 
+ * ~~ Wizard Simulator 20XX ~~
+ * this is my solution for this advent of code puzzle
+ * 
+ * by alex prosser
+ * 11/29/2023
+ */
+
+const spells = {
+    magic_missile: {
+        timer: 0,
+        cost: 53,
+        cast: (player, boss) => { boss.health -= 4; },
+        activate: (player, boss) => {},
+        finish: (player, boss) => {}
+    },
+    drain: {
+        timer: 0,
+        cost: 73,
+        cast: (player, boss) => { player.health += 2; boss.health -= 2; },
+        activate: (player, boss) => {},
+        finish: (player, boss) => {}
+    },
+    shield: {
+        timer: 6,
+        cost: 113,
+        cast: (player, boss) => { player.armor += 7; },
+        activate: (player, boss) => {},
+        finish: (player, boss) => { player.armor -= 7; }
+    },
+    poison: {
+        timer: 6,
+        cost: 173,
+        cast: (player, boss) => {},
+        activate: (player, boss) => { boss.health -= 3; },
+        finish: (player, boss) => {}
+    },
+    recharge: {
+        timer: 5,
+        cost: 229,
+        cast: (player, boss) => {},
+        activate: (player, boss) => { player.mana += 101; },
+        finish: (player, boss) => {}
+    }
+}
+
+const doRound = (state, spell) => {
+    // do current spell effects at player's turn
+    state.currentSpells.forEach(spellInfo => {
+        spells[spellInfo.name].activate(state.player, state.boss);
+        spellInfo.timer--;
+    });
+
+    // cast new spell
+    spells[spell].cast(state.player, state.boss);
+    state.player.mana -= spells[spell].cost;
+    state.manaCost += spells[spell].cost;
+    state.currentSpells.push({ name: spell, timer: spells[spell].timer });
+
+    // remove expired spells
+    let ongoing = state.currentSpells.map(spellInfo => {
+        if (spellInfo.timer <= 0) {
+            spells[spellInfo.name].finish(state.player, state.boss);
+            return null;
+        }
+        return spellInfo;
+    });
+    state.currentSpells = ongoing.filter(spell => spell);
+
+    // do current spell effects at boss's turn
+    state.currentSpells.forEach(spellInfo => {
+        spells[spellInfo.name].activate(state.player, state.boss);
+        spellInfo.timer--;
+    });
+
+    // remove expired spells
+    ongoing = state.currentSpells.map(spellInfo => {
+        if (spellInfo.timer <= 0) {
+            spells[spellInfo.name].finish(state.player, state.boss);
+            return null;
+        }
+        return spellInfo;
+    });
+    state.currentSpells = ongoing.filter(spell => spell);
+
+    // stop if boss has died
+    if (state.boss.health <= 0) return;
+
+    // do boss damage
+    state.player.health -= Math.max(state.boss.damage - state.player.armor, 1);
+}
+
+const simulateAllBattles = startingState => {
+    let minimum = Infinity;
+
+    const simulateBattle = (state, depth) => {
+        // stop the battle if health or mana is removed or if the cost is too high
+        if (state.player.health <= 0 || state.player.mana <= 0 || state.manaCost > minimum) return;
+
+        if (state.boss.health <= 0) {
+            // if boss dies, check to see how much mana it costs
+            minimum = Math.min(minimum, state.manaCost);
+            return;
+        }
+
+        // find all spells that can be casted and try them
+        let availableSpells = Object.keys(spells).filter(spell => {
+            for (let i = 0; i < state.currentSpells.length; i++) {
+                if (spell == state.currentSpells[i].name || state.player.mana < spells[spell].cost) return false;
+            }
+            return true;
+        });
+
+        availableSpells.forEach(spellName => {
+            let newState = structuredClone(state);
+            doRound(newState, spellName);
+            simulateBattle(newState, depth + 1);
+        });
+    }
+
+    simulateBattle(startingState, 0);
+    return minimum;
+}
+
+/**
+ * code for part 1 of the advent of code puzzle
+ * 
+ * @param {string} input 
+ * @returns {Promise<string | number>} the result of part 1
+ */
+const part1 = async input => {
+    let [bossHitPoints, bossDamage] = input.split(/\n/g).map(line => parseInt(line.split(': ')[1]));
+
+    const startingState = {
+        player: { health: 50, armor: 0, mana: 500 },
+        boss: { health: bossHitPoints, damage: bossDamage },
+        currentSpells: [],
+        manaCost: 0
+    }
+
+    return simulateAllBattles(startingState);
+}
+
+/**
+ * code for part 2 of the advent of code puzzle
+ * 
+ * @param {string} input 
+ * @returns {Promise<string | number>} the result of part 2
+ */
+const part2 = async input => {
+    return 0;
+}
+
+export { part1, part2 };