Files
AoC/2024/09/index.ts
2024-12-10 08:12:54 +00:00

103 lines
2.8 KiB
TypeScript

const fs = require('fs');
const input = fs.readFileSync(__dirname + '/input.txt', 'utf8');
interface MyFile { id: number, addr: number, size: number };
const freeSpaces: Array<{ addr: number, size: number }> = [];
const files: Array<MyFile> = [];
const reorderedFiles: Array<MyFile> = [];
let pointer = 0;
let id = 0;
for (let i = 0; i < input.length; i++) {
const size = parseInt(input[i]);
if (i % 2 === 0) {
files.push({ id, size, addr: pointer });
id++;
} else if (size) {
freeSpaces.push({ addr: pointer, size });
}
pointer += size;
}
const finalSpace = { addr: pointer, size: 0 };
if (input.length % 2 !== 0) {
freeSpaces.push(finalSpace);
}
function printDisk() {
const disk: Array<string> = [];
files.forEach((file) => {
for (let i = file.addr; i < file.addr + file.size; i++) {
disk[i] = ''+file.id;
}
});
reorderedFiles.forEach((file) => {
for (let i = file.addr; i < file.addr + file.size; i++) {
disk[i] = ''+file.id;
}
});
freeSpaces.forEach((space) => {
for (let i = space.addr; i < space.addr + space.size; i++) {
disk[i] = '.';
}
});
console.log(disk.join(''));
}
console.log(files);
while (true) {
const lastFile = files.pop()!;
let remainingSize = lastFile.size;
console.log(files, lastFile, freeSpaces);
while (remainingSize > 0) {
const firstFreeSpace = freeSpaces.shift()!;
let filePartSize;
let remainingFreeSpace;
if (remainingSize < firstFreeSpace.size) {
filePartSize = remainingSize;
remainingFreeSpace = firstFreeSpace.size - remainingSize;
} else {
filePartSize = firstFreeSpace.size;
remainingFreeSpace = 0;
}
reorderedFiles.push({ addr: firstFreeSpace.addr, id: lastFile.id, size: filePartSize });
finalSpace.size += filePartSize;
finalSpace.addr -= filePartSize;
remainingSize -= filePartSize;
if (remainingFreeSpace) {
freeSpaces.unshift({ addr: firstFreeSpace.addr + filePartSize, size: remainingFreeSpace });
}
}
let i = freeSpaces.length - 2;
if (!freeSpaces[i]) {
break;
}
while (freeSpaces[i].addr + freeSpaces[i].size === finalSpace.addr) {
finalSpace.addr = freeSpaces[i].addr;
finalSpace.size += freeSpaces[i].size;
freeSpaces[i] = finalSpace;
freeSpaces.pop();
i--;
}
}
let checksum = 0;
const allFiles = files.concat(reorderedFiles);
allFiles.sort((a, b) => a.addr - b.addr);
console.log(allFiles, freeSpaces);
allFiles.forEach((file) => {
for (let i = file.addr; i < file.addr + file.size; i++) {
checksum += i * file.id;
}
});
console.log(checksum);