Added the four first days of 2015

Yes i'm gonna do them all !

Signed-off-by: Avior <github@avior.me>

2015/day-1/part-1.ts

@@ -0,0 +1,8 @@
+import fs from 'fs'
+
+const input = fs.readFileSync(__dirname + '/input.txt').toString()
+	.split('')
+
+console.log(
+	"Result:", input.reduce((p, c) => p + (c === '(' ? 1 : -1), 0)
+)

2015/day-1/part-2.ts

@@ -0,0 +1,19 @@
+import fs from 'fs'
+
+const input = fs.readFileSync(__dirname + '/input.txt').toString()
+	.split('')
+
+let v = 0
+for (let i = 0; i < input.length; i++) {
+	const item = input[i];
+	if (item === '(') {
+		v++
+		continue
+	}
+	if (--v < 0) {
+		console.log(
+			"Result:", i + 1
+		)
+		break
+	}
+}

2015/day-2/part-1.ts

@@ -0,0 +1,17 @@
+import fs from 'fs'
+
+const input: Array<[number, number, number]> = fs.readFileSync(__dirname + '/input.txt').toString()
+	.split('\n')
+	.map((it) => it.split('x').map((v) => parseInt(v)) as [number, number, number])
+
+function calc(item: [number, number, number]) {
+	const l = item[0]
+	const w = item[1]
+	const h = item[2]
+	const smallestSide = Math.min(l*w, w*h, h*l)
+	return 2*l*w + 2*w*h + 2*h*l + smallestSide
+}
+
+console.log(
+	"Result:", input.reduce((p, c) => p + calc(c), 0)
+)

2015/day-2/part-2.ts

@@ -0,0 +1,18 @@
+import fs from 'fs'
+
+const input: Array<[number, number, number]> = fs.readFileSync(__dirname + '/input.txt').toString()
+	.split('\n')
+	.map((it) => it.split('x').map((v) => parseInt(v)) as [number, number, number])
+
+function calc(item: [number, number, number]) {
+	const l = item[0]
+	const w = item[1]
+	const h = item[2]
+	const largest = Math.max(l, w, h)
+	const tmp = l === largest ? w+h : w === largest ? l+h : l+w
+	return tmp + tmp + l*w*h
+}
+
+console.log(
+	"Result:", input.reduce((p, c) => p + calc(c), 0)
+)

2015/day-3/part-1.ts

@@ -0,0 +1,34 @@
+import fs from 'fs'
+
+const input = fs.readFileSync(__dirname + '/input.txt').toString()
+	.split('') as Array<'<' | '>' | 'v' | '^'>
+
+const poses: Array<`${number}:${number}`> = ['0:0']
+
+let x = 0
+let y = 0
+
+for (const direction of input) {
+	switch (direction) {
+		case '>':
+			x++
+			break;
+		case '<':
+			x--
+			break;
+		case '^':
+			y--
+			break;
+		case 'v':
+			y++
+			break;
+	}
+	const v: `${number}:${number}` = `${x}:${y}`
+	if (!poses.includes(v)) {
+		poses.push(v)
+	}
+}
+
+console.log(
+	"Result:", poses.length
+)

2015/day-3/part-2.ts

@@ -0,0 +1,49 @@
+import fs from 'fs'
+
+const input = fs.readFileSync(__dirname + '/input.txt').toString()
+	.split('') as Array<'<' | '>' | 'v' | '^'>
+
+const poses: Array<`${number}:${number}`> = ['0:0']
+
+let x = 0
+let y = 0
+
+let roboX = 0
+let roboY = 0
+
+for (let i = 0; i < input.length; i++) {
+	const direction = input[i]
+	let xChange = 0
+	let yChange = 0
+	switch (direction) {
+		case '>':
+			xChange++
+			break;
+		case '<':
+			xChange--
+			break;
+		case '^':
+			yChange--
+			break;
+		case 'v':
+			yChange++
+			break;
+	}
+	let v: `${number}:${number}`
+	if (i % 2 === 0) { // santa
+		x += xChange
+		y += yChange
+		v = `${x}:${y}`
+	} else { // roboSanta
+		roboX += xChange
+		roboY += yChange
+		v = `${roboX}:${roboY}`
+	}
+	if (!poses.includes(v)) {
+		poses.push(v)
+	}
+}
+
+console.log(
+	"Result:", poses.length
+)

2015/day-4/part-1.ts

@@ -0,0 +1,16 @@
+import crypto from 'crypto'
+
+
+// const input = "pqrstuv"
+const input = "yzbqklnj"
+
+let hash = ""
+let i = 0
+do {
+	hash = crypto.createHash('md5').update(input + ++i).digest('hex')
+} while (!hash.startsWith('00000'))
+
+
+console.log(
+	"Result:", i, hash
+)

2015/day-4/part-2.ts

@@ -0,0 +1,16 @@
+import crypto from 'crypto'
+
+
+// const input = "pqrstuv"
+const input = "yzbqklnj"
+
+let hash = ""
+let i = 0
+do {
+	hash = crypto.createHash('md5').update(input + ++i).digest('hex')
+} while (!hash.startsWith('000000'))
+
+
+console.log(
+	"Result:", i, hash
+)