96 lines
2.0 KiB
TypeScript
96 lines
2.0 KiB
TypeScript
function hash(s: string) {
|
|
let ret = 0;
|
|
for (let i = 0; i < s.length; i++) {
|
|
const ch = s.charCodeAt(i);
|
|
ret += ch;
|
|
ret *= 17;
|
|
ret %= 256;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
type Inst = {
|
|
kind: "remove",
|
|
lens: string
|
|
} | {
|
|
kind: "add",
|
|
lens: string,
|
|
/**
|
|
* focal length
|
|
* 1-9
|
|
*/
|
|
focal: number,
|
|
}
|
|
|
|
function decodeInst(input: string): Inst {
|
|
if (input.endsWith("-")) {
|
|
return {
|
|
kind: "remove",
|
|
lens: input.slice(0, -1)
|
|
}
|
|
}
|
|
const [lens, focal] = input.split("=");
|
|
return {
|
|
kind: "add",
|
|
lens,
|
|
focal: parseInt(focal)
|
|
}
|
|
}
|
|
|
|
type Slot = {
|
|
lens: string,
|
|
focal: number
|
|
}
|
|
|
|
|
|
|
|
type State = {
|
|
boxes: Slot[][]
|
|
}
|
|
|
|
function executeInst(state: State, inst: Inst) {
|
|
const boxIndex = hash(inst.lens);
|
|
if (inst.kind === "add") {
|
|
const slotIndex = state.boxes[boxIndex].findIndex(x => x.lens === inst.lens);
|
|
if (slotIndex === -1) {
|
|
state.boxes[boxIndex].push({
|
|
lens: inst.lens,
|
|
focal: inst.focal
|
|
});
|
|
} else {
|
|
state.boxes[boxIndex][slotIndex].focal = inst.focal;
|
|
}
|
|
}
|
|
else if (inst.kind === "remove") {
|
|
const slotIndex = state.boxes[boxIndex].findIndex(x => x.lens === inst.lens);
|
|
if (slotIndex !== -1) {
|
|
state.boxes[boxIndex].splice(slotIndex, 1);
|
|
}
|
|
}
|
|
}
|
|
|
|
function initState(): State {
|
|
return {
|
|
boxes: new Array(256).fill(0).map(() => [])
|
|
}
|
|
}
|
|
|
|
const input = await Deno.readTextFile("input.txt");
|
|
const inputs = input.split(",");
|
|
|
|
const insts = inputs.map(decodeInst);
|
|
const state = initState();
|
|
|
|
for (const inst of insts) {
|
|
executeInst(state, inst);
|
|
}
|
|
|
|
console.log(state);
|
|
|
|
function calculateFocusingPower(state: State) {
|
|
return state.boxes.map((slots, i) => slots.map((slot, j) => slot.focal * (j + 1) * (i + 1))
|
|
.reduce((a, b) => a + b, 0))
|
|
.reduce((a, b) => a + b, 0)
|
|
}
|
|
|
|
console.log(calculateFocusingPower(state)) |