part-one.js

const { input } = require('./input');

let count = {};

for (let line of input) {
	for (let i = 0; i < line.length; i++) {
		if (!count[i]) {
			// Initialize [zeros_count, ones_count]
			count[i] = [0, 0];
		}

		let val = +line[i];
		count[i][val]++;
	}
}

let mins = [];
let maxs = [];
for (let counts of Object.values(count)) {
	if (counts[0] > counts[1]) {
		maxs.push(0);
		mins.push(1);
	} else {
		maxs.push(1);
		mins.push(0);
	}
}

let min = parseInt(mins.join(''), 2);
let max = parseInt(maxs.join(''), 2);

console.log(min * max);