Day 16

day16/common/volcano.go

@@ -0,0 +1,219 @@
+package common
+
+import (
+	"bufio"
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+
+type Valve struct {
+  name string
+  rate int
+  tunnels map[*Valve]struct{}
+  distances map[*Valve]int
+}
+
+func (valve *Valve) GetBestPathFromValveWithHelper(otherValves map[*Valve]int, minutesLeft int, helperValve *Valve, helperMinutesLeft int) int {
+  max := 0
+  current := 0
+
+  if minutesLeft > 0 {
+    current += (minutesLeft - 1) * valve.rate
+  }
+  if helperMinutesLeft > 0 {
+    current += (helperMinutesLeft - 1) * helperValve.rate
+  }
+
+  if minutesLeft > 0 || helperMinutesLeft > 0 {
+    for relevantValve := range(otherValves) {
+      done := false
+      if minutesLeft <= 0 {
+        done = true
+      }
+      if minutesLeft - valve.distances[relevantValve] <= 0 {
+        relevantValve = valve
+        minutesLeft = 0
+      }
+
+      for relevantValve2 := range(otherValves) {
+        helperDone := false
+        if helperMinutesLeft <= 0 {
+          helperDone = true
+        }
+        if helperMinutesLeft - helperValve.distances[relevantValve2] <= 0 {
+          relevantValve2 = helperValve
+          helperMinutesLeft = 0
+        }
+
+        if relevantValve != relevantValve2 {
+          currentRelevantValves := make(map[*Valve]int)
+          for relevantValve3, relevantValveRate3 := range(otherValves) {
+            if relevantValve != relevantValve3 && relevantValve2 != relevantValve3 {
+              currentRelevantValves[relevantValve3] = relevantValveRate3
+            }
+          }
+          currentMax := relevantValve.GetBestPathFromValveWithHelper(currentRelevantValves, minutesLeft - 1 - valve.distances[relevantValve],
+                                                                     relevantValve2, helperMinutesLeft - 1 - helperValve.distances[relevantValve2])
+          if currentMax > max {
+            max = currentMax
+          }
+        } else if len(otherValves) == 1 {
+          currentMax := relevantValve.GetBestPathFromValveWithHelper(make(map[*Valve]int), minutesLeft - 1 - valve.distances[relevantValve],
+                                                                     helperValve, 0)
+          if currentMax > max {
+            max = currentMax
+          }
+          currentMax = valve.GetBestPathFromValveWithHelper(make(map[*Valve]int), 0,
+                                                            relevantValve2, helperMinutesLeft - 1 - helperValve.distances[relevantValve2])
+          if currentMax > max {
+            max = currentMax
+          }
+        }
+
+        if helperDone {
+          break
+        }
+      }
+
+      if done {
+        break
+      }
+    }
+  }
+
+  return max + current
+}
+
+func (valve *Valve) GetBestPathFromValve(otherValves map[*Valve]int, minutesLeft int) int {
+  if minutesLeft <= 0 {
+    return 0
+  }
+
+  current := (minutesLeft - 1) * valve.rate
+  max := 0
+
+  for relevantValve := range(otherValves) {
+    currentRelevantValves := make(map[*Valve]int)
+    for relevantValve2, relevantValveRate2 := range(otherValves) {
+      if relevantValve != relevantValve2 {
+        currentRelevantValves[relevantValve2] = relevantValveRate2
+      }
+    }
+    currentMax := relevantValve.GetBestPathFromValve(currentRelevantValves, minutesLeft - 1 - valve.distances[relevantValve])
+    if currentMax > max {
+      max = currentMax
+    }
+  }
+
+  return max + current
+}
+
+
+type Volcano struct {
+  valves []*Valve
+  current *Valve
+  rate int
+  pressure int
+  minutesLeft int
+}
+
+func (volcano *Volcano) GetBestPath(minutesLeft int, helper bool) int {
+  relevantValves := make(map[*Valve]int)
+  for valve := range volcano.valves {
+    if volcano.valves[valve].rate > 0 {
+      relevantValves[volcano.valves[valve]] = volcano.valves[valve].rate
+    }
+  }
+
+  if helper {
+    return volcano.current.GetBestPathFromValveWithHelper(relevantValves, minutesLeft + 1, volcano.current, minutesLeft + 1)
+  } else {
+    return volcano.current.GetBestPathFromValve(relevantValves, minutesLeft + 1)
+  }
+}
+
+func (volcano *Volcano) ComputeDistances() bool {
+  changesFound := false
+  for valveSource := range volcano.valves {
+    for valveTarget1 := range volcano.valves[valveSource].distances {
+      for valveTarget2 := range volcano.valves[valveSource].distances {
+        d, ok := valveTarget1.distances[valveTarget2]
+        newDistance := volcano.valves[valveSource].distances[valveTarget1] +
+                       volcano.valves[valveSource].distances[valveTarget2]
+        if !ok || newDistance < d {
+          valveTarget1.distances[valveTarget2] = newDistance
+          valveTarget2.distances[valveTarget1] = newDistance
+          changesFound = true
+        }
+      }
+    }
+  }
+  return changesFound
+}
+
+func (volcano *Volcano) Print() {
+  for i := range(volcano.valves) {
+    fmt.Print(volcano.valves[i].name)
+    fmt.Print(": ")
+    fmt.Println(volcano.valves[i].rate)
+    for valve, d := range(volcano.valves[i].distances) {
+      fmt.Print("  ")
+      fmt.Print(valve.name)
+      fmt.Print(": ")
+      fmt.Println(d)
+    }
+  }
+}
+
+
+func Parse(scanner bufio.Scanner) Volcano {
+  volcano := Volcano{}
+  volcano.valves = []*Valve{}
+  destinations := make(map[string][]string)
+
+  for scanner.Scan() {
+    line := scanner.Text()
+    splittedLine := strings.Split(line, " ")
+    name := splittedLine[1]
+    rate, _ := strconv.Atoi(splittedLine[4][5:len(splittedLine[4])-1])
+    destinations[name] = []string{}
+    for i := 9; i < len(splittedLine); i++ {
+      destinations[name] = append(destinations[name], splittedLine[i][0:2])
+    }
+    volcano.valves = append(volcano.valves, &Valve{name, rate, map[*Valve]struct{}{}, make(map[*Valve]int)})
+  }
+
+  for valveName, currDestinations := range(destinations) {
+    var valveSource *Valve
+    for i := range volcano.valves {
+      if volcano.valves[i].name == valveName {
+        valveSource = volcano.valves[i]
+        valveSource.distances[valveSource] = 0
+        break
+      }
+    }
+    for _, destination := range currDestinations {
+      var valveDestination *Valve
+      for i := range volcano.valves {
+        if volcano.valves[i].name == destination {
+          valveDestination = volcano.valves[i]
+        }
+      }
+      valveSource.tunnels[valveDestination] = struct{}{}
+      valveSource.distances[valveDestination] = 1
+    }
+  }
+
+  for i := range(volcano.valves) {
+    if volcano.valves[i].name == "AA" {
+      volcano.current = volcano.valves[i]
+    }
+  }
+  volcano.minutesLeft = 30
+
+  for volcano.ComputeDistances() {}
+
+  return volcano
+}