Advent of Code 2018 Solutions

day1-puzzle1.js

fetch('https://adventofcode.com/2018/day/1/input')
.then(res => {
    // convert html response body to text
    res.text().then(rawData => {
	// convert rawData to array
	const data = rawData.trim().split('\n').map(elem => parseInt(elem));
	console.log(data);
	localStorage.setItem('advofcode-puzzle1', JSON.stringify(data)); // store item in localstorage

	// reduce data into single value
	const result = data.reduce((accumulator, currentValue) => accumulator + currentValue);
	console.log(result);
    });
}) 

day1-puzzle2.js

// convert rawData to array
const data = JSON.parse(localStorage.getItem('advofcode-puzzle1'));
console.log(data);

let freqObj = [0];
let counter = 1;
let curFreq = data[0];
let iter = 0;
const maxLen = data.length - 1;

while (freqObj.indexOf(curFreq) === -1) {
    freqObj.push(curFreq);
    curFreq+= data[counter];
    const existFreq = freqObj.indexOf(curFreq);
    if (existFreq > -1) console.log(curFreq, existFreq, freqObj.length);

    if (counter === maxLen) {
        iter++;
        counter = 0; // reset counter
    } else {
        counter++;
    }

}

console.log('first repeated frequency is', curFreq);

day2-puzzle1.js

fetch('https://adventofcode.com/2018/day/1/input')
.then(res => {
    // convert html response body to text
    res.text().then(rawData => {
        // convert rawData to array
        const data = rawData.trim().split('\n').map(elem => parseInt(elem));
        console.log(data);
        localStorage.setItem('advofcode-puzzle1', JSON.stringify(data)); // store item in localstorage
    });
});

(function(){
	const data = JSON.parse(localStorage.getItem('advofcode-puzzle2'));
	// 	console.log(data)

	let twolettercount = 0;
	let threelettercount = 0;
	data.map(elem => {
		const letters = elem.split('').sort();
		
		let dupes = [];
		let dupeObj = {};
		letters.map((elem, i) => {
			if (elem === letters[i+1]) {
				dupes.push(elem);
			}
		});

		if (dupes.length) {
			// count similar letters in dupes
			dupes.map(elem => {
				if (!dupeObj[elem]) {
					dupeObj[elem] = 2;
				} else {
					dupeObj[elem]++;
                }
			});
// 			console.log(dupes, dupeObj, Object.values(dupeObj));

			let has3letters = false;
			let has2letters = false;
			Object.values(dupeObj).map(elem => {
				if (elem > 2) {has3letters = true}
				if (elem == 2) {has2letters = true}
			});

			if (has3letters) {
				threelettercount++;
			}

			if (has2letters) {
				twolettercount++;
			}
        }
	});

	console.log(twolettercount, threelettercount, twolettercount * threelettercount);
	console.log('checksum is', twolettercount * threelettercount);
})();

day2-puzzle2.js

(function(){
	const data = JSON.parse(localStorage.getItem('advofcode-puzzle2'));
    console.log(data.length);

	const letterArr = data.map(elem => {
		return elem.split('');
	});

	// console.log(letterArr);
	const differences = [];
	letterArr.map((word, i) => {
		const letterArr2 = [...letterArr];
		letterArr2.splice(i,1);
		console.log(letterArr2.length);
		letterArr2.map(nextword => {
			const worddiff = [];
			word.map((char, k) => {
                if (char !== nextword[k]) {
                    worddiff.push({
                        diffId: k,
                        arr1: char,
                        arr2: nextword[k]
                    });
                }
            });
            differences.push({
                str1: word.join(''),
                str2: nextword.join(''),
                diff: worddiff
            });
		});
            
	});

	console.log(differences);

	// find items with 1 difference only
	const singledifference = differences.filter(elem => {
		return elem.diff.length === 1;
	});

	console.log(singledifference);
	// check if singledifferences contain only 2 matching items and that both are equal
	if (singledifference.length === 2 && singledifference[0].str1 === singledifference[1].str2 && singledifference[0].str1 === singledifference[1].str2) {
	console.log('found! difference:', singledifference[0].diff);
	// get common letters from strings by testing first match
	const firstString = singledifference[0];
	const commonletters = firstString.str1.split('');
	commonletters.splice(singledifference[0].diff[0].diffId,1);
	// console.log(commonletters);
	// console.log(commonletters.join(''));

	console.log('answer', commonletters.join(''));
    }
})();

day3-puzzle1.js

fetch('https://adventofcode.com/2018/day/3/input')
.then(res => {
    // convert html response body to text
    res.text().then(rawData => {
        // convert rawData to array
        const data = rawData.trim().split('\n').map(elem => {
			return {
				id: parseInt(elem.split(' @')[0].split('#')[1]),
				coordinates: {
					x: parseInt(elem.split(' @ ')[1].split(',')[0]),
					y: parseInt(elem.split(' @ ')[1].split(',')[1].split(':')[0])
				},
				dimensions: {
					width: parseInt(elem.split(' @ ')[1].split(',')[1].split(': ')[1].split('x')[0]),
					height: parseInt(elem.split(' @ ')[1].split(',')[1].split(': ')[1].split('x')[1])
				}
			};
		});
        console.log(data);
        localStorage.setItem('advofcode-puzzle3', JSON.stringify(data)); // store item in localstorage
    });
});