Previous years crap.

Signed-off-by: Ettore Dreucci <ettore.dreucci@gmail.com>

2018/day_11/main.go

@@ -0,0 +1,98 @@
+package main
+
+import (
+	"fmt"
+	"math"
+)
+
+const gridSize int = 300
+const gridSerial int = 7347
+
+func cellPower(x int, y int, serial int) int {
+	rackID := x + 1 + 10
+	powerLevel := rackID * (y + 1)
+	powerLevel += serial
+	powerLevel *= rackID
+	powerLevel %= int(math.Pow(10, 3))
+	powerLevel /= int(math.Pow(10, 2))
+
+	return powerLevel
+}
+
+func maxPowerSquare(powerGrid *[gridSize][gridSize]int, powerGridCheck *[gridSize][gridSize]bool, size int, res chan<- [4]int) {
+	maxSum := 0
+	maxSumCheck := false
+	maxX, maxY := 0, 0
+
+	for x := 0; x < gridSize-size+1; x++ {
+		for y := 0; y < gridSize-size+1; y++ {
+			powerSum := 0
+			for xi := x; xi < x+size; xi++ {
+				for yi := y; yi < y+size; yi++ {
+					if !powerGridCheck[xi][yi] {
+						powerGrid[xi][yi] = cellPower(xi, yi, gridSerial)
+						powerGridCheck[xi][yi] = true
+					}
+					powerSum += powerGrid[xi][yi]
+				}
+			}
+			if powerSum > maxSum || !maxSumCheck {
+				maxSum = powerSum
+				maxSumCheck = true
+				maxX = x
+				maxY = y
+			}
+		}
+	}
+	res <- [4]int{size, maxSum, maxX + 1, maxY + 1}
+}
+
+func main() {
+
+	var powerGrid [gridSize][gridSize]int
+	var powerGridCheck [gridSize][gridSize]bool
+	var res = make(chan [4]int)
+
+	go func() {
+		maxPowerSquare(&powerGrid, &powerGridCheck, 3, res)
+		close(res)
+	}()
+	p1 := <-res
+	fmt.Printf("Part One: %v,%v\n", p1[2], p1[3])
+
+	res = make(chan [4]int)
+	for i := 0; i < gridSize; i++ {
+		go func(i int) {
+			maxPowerSquare(&powerGrid, &powerGridCheck, i, res)
+			if i == gridSize-1 {
+				close(res)
+			}
+		}(i)
+	}
+
+	maxSum := 0
+	maxSumCheck := false
+	maxX, maxY := 0, 0
+	maxSize := 0
+
+	for r := range res {
+		fmt.Printf("Size: %v\t Sum: %v\t x: %v\t y: %v\n", r[0], r[1], r[2], r[3])
+		if r[1] > maxSum || !maxSumCheck {
+			maxSize = r[0]
+			maxSum = r[1]
+			maxSumCheck = true
+			maxX = r[2]
+			maxY = r[3]
+		}
+	}
+	fmt.Printf("Part Two: %v,%v,%v\n", maxX, maxY, maxSize)
+
+	res = make(chan [4]int)
+	go func() {
+		maxPowerSquare(&powerGrid, &powerGridCheck, 299, res)
+		close(res)
+	}()
+	p1 = <-res
+	fmt.Printf("Part Two 299: %v,%v,%v\n", p1[1], p1[2], p1[3])
+
+}

2018/day_11/prova.go

@@ -0,0 +1,77 @@
+package main
+
+import (
+	"fmt"
+	"strconv"
+)
+
+func calculate(i int, j int, memo *[][]int, ps *[][]int, input int) int {
+	t := 0
+	for x := i; x < i+3; x++ {
+		for y := j; y < j+3; y++ {
+			if (*memo)[y][x] != 0 {
+				t += (*memo)[y][x]
+			} else {
+				id := x + 10
+				serial := (id*y + input)
+				hundreds := strconv.Itoa(serial * id)
+				var result int
+				if len(hundreds) >= 3 {
+					result, _ = strconv.Atoi(string(hundreds[len(hundreds)-3]))
+				}
+				result -= 5
+				t += result
+				(*memo)[y][x] = result
+				(*ps)[y][x] = result + (*ps)[y-1][x] + (*ps)[y][x-1] - (*ps)[y-1][x-1]
+			}
+		}
+	}
+	return t
+}
+
+func main() {
+
+	input := 7347
+
+	var res, X, Y int
+
+	// technically memo isn't needed anymore but I added partial sums after
+	// part 2 and didn't wanna clean up my code after for part 1
+	memo := make([][]int, 301)
+	partialSums := make([][]int, 301)
+	for i := range memo {
+		memo[i] = make([]int, 301)
+		partialSums[i] = make([]int, 301)
+	}
+
+	for i := 1; i <= 298; i++ {
+		for j := 1; j <= 298; j++ {
+			if c := calculate(i, j, &memo, &partialSums, input); c > res {
+				res = c
+				X = i
+				Y = j
+			}
+		}
+	}
+
+	fmt.Printf("Part 1: %v, %v, %v\n", res, X, Y)
+
+	res = 0
+	var sz int
+
+	for size := 1; size < 300; size++ {
+		for i := size; i <= 300; i++ {
+			for j := size; j <= 300; j++ {
+				if c := partialSums[i][j] - partialSums[i-size][j] -
+					partialSums[i][j-size] + partialSums[i-size][j-size]; c > res {
+					res = c
+					Y = i - size + 1
+					X = j - size + 1
+					sz = size
+				}
+			}
+		}
+	}
+
+	fmt.Printf("Part 2: %v, %v, %v, %v\n", res, X, Y, sz)
+}