adventofcode.js

// DAY 3
(function(rows) {
	let claims = Array.from(Array(1000).keys()).map(() => Array(1000).fill(0));
	for (let row of rows) {
		let [ , , loc, size ] = row;
		loc = loc.split(',').map(Number);
		size = size.split('x').map(Number);
		for (let i = 0; i < size[0]; i++) {
			let claimRow = claims[loc[0] + i];
			for (let j = 0; j < size[1]; j++) {
					claimRow[loc[1] + j]++;
			}
		}
	}
	let count = claims.map(claimRow => claimRow.filter(x => x > 1).length).reduce((a, b) => a + b);
	console.log(count);

	for (let row of rows) {
		let [ id, , loc, size ] = row;
		loc = loc.split(',').map(Number);
		size = size.split('x').map(Number);
		let valid = true;
		for (let i = 0; i < size[0] && valid; i++) {
			let claimRow = claims[loc[0] + i];
			valid &= claimRow.slice(loc[1], loc[1] + size[1]).every(x => x == 1);
		}
		if (valid) {
			console.log(id);
		}
	}
})(document.body.innerText.trim().split('\n').map(row => row.split(/:?\s+/)));

// DAY 4
//TODO

// DAY 5
(function(all_units) {
	let best = 1e99;
	for (let c = 65; c <= 90; c++) {
		let char = String.fromCharCode(c);
		let units = all_units.filter(x => x.toUpperCase() != char);
		for (let i = 1; i < units.length; i++) {
			while (0 < i && i < units.length && units[i] != units[i - 1] && units[i].toUpperCase() == units[i - 1].toUpperCase()) {
				units.splice(i - 1, 2);
				i--;
			}
		}
		if (units.length < best)
			best = units.length;
		console.log(char, units.length, best);
	}
	console.log(best);
})(Array.from(document.body.innerText.trim()));