AOC202101.js

const input = `103
106
107
110
121
132
147
148
...
9548`;

const test = `199
200
208
210
200
207
240
269
260
263`;

// SPLIT LINES
// const lines = test.split('\n');
const lines = input.split('\n');

// SPLIT CHARS
// const chars = test.split('');
// const chars = input.split('');

// PARSE CHARS
// const parsed = chars.map(char => parseInt(char));
// PARSE LINES
const parsed = lines.map(line => parseInt(line));

// Part 1:
function puzzle1() {
    let count = 0;
    for (let i = 1; i < parsed.length; i++) {
        if (parsed[i] > parsed[i - 1]) {
            count++;
        }
    }
    return count;
}

const part1 = puzzle1();
console.log('Part 1:', part1);

// Part 2:
function puzzle2() {
    let count = 0;
    let sum = parsed[0] + parsed[1] + parsed[2];
    for (let i = 3; i < parsed.length; i++) {
        let newsum = parsed[i-2] + parsed[i-1] + parsed[i];
        if (newsum > sum) {
            count++;
        }
        sum = newsum;
    }
    return count;
}

const part2 = puzzle2();
console.log('Part 2:', part2);