93 lines
2.2 KiB
JavaScript
93 lines
2.2 KiB
JavaScript
|
const fs = require('fs/promises');
|
||
|
|
|
||
|
|
const sum = (arr) => arr.reduce((total, num) => total+num, 0);
|
||
|
|
const arrayOfLength = n => Array.from(Array(n).keys()).map(() => {});
|
||
|
|
|
||
|
|
const main = async () => {
|
||
|
|
const input = (await fs.readFile("./input.txt", 'utf8')).split("\n");
|
||
|
|
|
||
|
|
const coord = ([x, y]) => {
|
||
|
|
|
||
|
|
if(isNaN(x) || typeof y === "undefined") {
|
||
|
|
throw new Error("");
|
||
|
|
}
|
||
|
|
return `${x}-${y}`;
|
||
|
|
};
|
||
|
|
|
||
|
|
let sandUnitCount = 0;
|
||
|
|
|
||
|
|
|
||
|
|
const fillPath = ([x1, y1], [x2, y2]) => {
|
||
|
|
const fillIns = [];
|
||
|
|
if(x1 === x2) {
|
||
|
|
const yDiff = y2 - y1;
|
||
|
|
for(let y = y1; y !== y2; y = y + (Math.abs(yDiff)/yDiff)) {
|
||
|
|
fillIns.push(coord([x1, y]));
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
const xDiff = x2 - x1;
|
||
|
|
|
||
|
|
for(let x = x1; x !== x2; x = x + (xDiff/Math.abs(xDiff))) {
|
||
|
|
fillIns.push(coord([x, y1]));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return fillIns;
|
||
|
|
|
||
|
|
};
|
||
|
|
const grid = input.reduce((obj, row, i) => {
|
||
|
|
if(row === "" ) {
|
||
|
|
return obj;
|
||
|
|
}
|
||
|
|
const path = row.split(" -> ");
|
||
|
|
for(let i = 0; i < path.length - 1; i++) {
|
||
|
|
const start = path[i].split(",").map(x => parseInt(x));
|
||
|
|
const end = path[i + 1].split(",").map(x => parseInt(x));
|
||
|
|
|
||
|
|
const filledIn = fillPath(start, end);
|
||
|
|
filledIn.forEach(x => obj[x] = "#")
|
||
|
|
}
|
||
|
|
const lastRock = path[path.length - 1].split(",").map(x => parseInt(x))
|
||
|
|
obj[coord(lastRock)] = "#";
|
||
|
|
|
||
|
|
return obj;
|
||
|
|
}, {})
|
||
|
|
|
||
|
|
const sandFall = (x, y) => {
|
||
|
|
if(y === 174) {
|
||
|
|
return [x, y];
|
||
|
|
}
|
||
|
|
if(!grid[coord([x, y + 1])]) {
|
||
|
|
return sandFall(x, y + 1);
|
||
|
|
}
|
||
|
|
if(!grid[coord([x - 1, y + 1])]) {
|
||
|
|
return sandFall(x - 1, y + 1);
|
||
|
|
}
|
||
|
|
if(!grid[coord([x + 1, y + 1])]) {
|
||
|
|
return sandFall(x + 1, y + 1);
|
||
|
|
}
|
||
|
|
return [x, y];
|
||
|
|
};
|
||
|
|
|
||
|
|
const print = () => {
|
||
|
|
for(let y = 0; y < 175; ++y) {
|
||
|
|
console.log(arrayOfLength(100).map((_, i) => grid[coord([i + 450, y])] || ".").join(""));
|
||
|
|
}
|
||
|
|
console.log("\n\n\n")
|
||
|
|
console.log("Sand count: ", sandUnitCount);
|
||
|
|
};
|
||
|
|
|
||
|
|
while(true) {
|
||
|
|
const loc = sandFall(500, 0);
|
||
|
|
sandUnitCount++;
|
||
|
|
grid[coord(loc)] = "o";
|
||
|
|
console.log("Location of sand: ", loc);
|
||
|
|
if(loc[0] === 500 && loc[1] === 0) {
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
console.log("Answer: ", sandUnitCount);
|
||
|
|
print();
|
||
|
|
}
|
||
|
|
|
||
|
|
main();
|