initialise

6/main.go

@@ -0,0 +1,160 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strings"
+)
+
+func findPosition(layout [][]string) []int {
+  position := []int{}
+  for i := range layout {
+    for j := range layout[i] {
+      if layout[i][j] == "^" {
+        position = append(position, i, j)
+      }
+    }
+  }
+  return position
+}
+
+func findObstacles(layout [][]string) [][]int {
+  positions := [][]int{}
+  for i := range layout {
+    for j := range layout[i] {
+      if layout[i][j] == "#" {
+        positions = append(positions, []int{i,j})
+      }
+    }
+  }
+  return positions
+}
+
+func calcPath(layout [][]string) ([][]int, bool) {
+  circle := false
+  direction := "up"
+  guardPosition:=findPosition(layout)
+  inBound := true
+  currentPosition := guardPosition
+  path := [][]int{currentPosition}
+  for inBound && !circle {
+    if direction == "up" {
+      if currentPosition[0] == 0 {
+        inBound = false
+        break
+      } else if layout[currentPosition[0]-1][currentPosition[1]] == "#" {
+        direction = "right"
+        continue
+      } else {
+        currentPosition = []int{currentPosition[0]-1, currentPosition[1]}
+        if checkCircle(path, currentPosition) {
+          circle = true
+        } else {
+          path = append(path, currentPosition)
+        }
+      }
+    }
+    if direction == "right" {
+      if currentPosition[1] == len(layout)-1 {
+        inBound = false
+        break
+      } else if layout[currentPosition[0]][currentPosition[1]+1] == "#" {
+        direction = "down"
+        continue
+      } else {
+        currentPosition = []int{currentPosition[0], currentPosition[1]+1}
+        if checkCircle(path, currentPosition) {
+          circle = true
+        } else {
+          path = append(path, currentPosition)
+        }
+      }
+    }
+    if direction == "down" {
+      if currentPosition[0] == len(layout)-1 {
+        inBound = false
+        break
+      } else if layout[currentPosition[0]+1][currentPosition[1]] == "#" {
+        direction = "left"
+        continue
+      } else {
+        currentPosition = []int{currentPosition[0]+1, currentPosition[1]}
+        if checkCircle(path, currentPosition) {
+          circle = true
+        } else {
+          path = append(path, currentPosition)
+        }
+      }
+    }
+    if direction == "left" {
+      if currentPosition[1] == 0 {
+        inBound = false
+        break
+      } else if layout[currentPosition[0]][currentPosition[1]-1] == "#" {
+        direction = "up"
+        continue
+      } else {
+        currentPosition = []int{currentPosition[0], currentPosition[1]-1}
+        if checkCircle(path, currentPosition) {
+          circle = true
+        } else {
+          path = append(path, currentPosition)
+        }
+      }
+    }
+  }
+  return path, circle
+}
+
+func checkCircle(path [][]int, position []int) bool {
+  result := false
+  for i:=1;i<len(path);i++  {
+    if path[i][0] == position[0] && path[i][1] == position[1] {
+      if i < len(path)-1 && path[i-1][0] == path[len(path)-1][0] && path[i-1][1] == path[len(path)-1][1] {
+        result = true
+      }
+    }
+  }
+  return result
+}
+
+func main() {
+  file, _ := os.Open("input")
+  defer file.Close()
+  scanner := bufio.NewScanner(file)
+  layout := [][]string{}
+  for scanner.Scan() {
+    line := scanner.Text()
+    layout = append(layout, strings.Split(line, ""))
+  }
+//  fmt.Println(path)
+//  fmt.Println(len(path))
+  path, _ := calcPath(layout)
+  pathOccurances := make(map[[2]int]int)
+  for _, tuple := range path {
+    key := [2]int{tuple[0],tuple[1]}
+    pathOccurances[key]++
+  }
+  fmt.Println(len(pathOccurances))
+  circleSpots := [][]int{}
+  for i:=1;i<len(path);i++ {
+    if path[i][0] == path[0][0] && path[i][1] == path[0][1] {
+      continue
+    } else {
+      tempValue := layout[path[i][0]][path[i][1]]
+      layout[path[i][0]][path[i][1]] = "#"
+      _, circle := calcPath(layout)
+      if circle {
+        circleSpots = append(circleSpots, path[i])
+      }
+      layout[path[i][0]][path[i][1]] = tempValue
+    }
+  }
+  uniqueCircles := make(map[[2]int]int)
+  for _, tuple := range circleSpots {
+    key := [2]int{tuple[0],tuple[1]}
+    uniqueCircles[key]++
+  }
+  fmt.Println(len(uniqueCircles))
+}