2018 day 24 More work

2018/day24/army.go

@@ -1,6 +1,17 @@
 package main
 
+import (
+	"fmt"
+	"strings"
+)
+
+const (
+	ArmyTypeImmune = 1 << iota
+	ArmyTypeInfection
+)
+
 type Army struct {
+	id          int
 	tp          int
 	units       int
 	hp          int
@@ -9,11 +20,14 @@ type Army struct {
 	damageType  string
 	strength    int
 	init        int
+	target      *Army
+	targettedBy *Army
 }
 
-func NewArmy(inp string, tp int) *Army {
+func NewArmy(inp string, tp, id int) *Army {
 	a := new(Army)
 	a.tp = tp
+	a.id = id
 
 	// Pull the parenthetical out, if one is there
 	var prnth, other string
@@ -50,8 +64,10 @@ func NewArmy(inp string, tp int) *Army {
 		for _, v := range strings.Fields(prnth) {
 			if v == "immune" {
 				inImmune = true
+				continue
 			} else if v == "weak" {
 				inImmune = false
+				continue
 			}
 			if v == "to" {
 				continue
@@ -69,12 +85,126 @@ func NewArmy(inp string, tp int) *Army {
 	return a
 }
 
+func (a *Army) IsImmuneTo(val string) bool {
+	for _, v := range a.immunities {
+		if v == val {
+			return true
+		}
+	}
+	return false
+}
+
+func (a *Army) IsWeakTo(val string) bool {
+	for _, v := range a.weaknesses {
+		if v == val {
+			return true
+		}
+	}
+	return false
+}
+
 func (a *Army) Power() int {
 	return a.units * a.strength
 }
 
+func (a *Army) FindTarget(group []*Army) {
+	var tgt *Army
+	var tgtDmg int
+	for _, v := range group {
+		if v.targettedBy != nil {
+			continue
+		}
+		wrkDmg := a.CalculateDamage(v)
+		if tgt == nil || wrkDmg > tgtDmg {
+			tgt = v
+			tgtDmg = wrkDmg
+		} else if wrkDmg == tgtDmg {
+			if v.Power() > tgt.Power() {
+				tgt = v
+				tgtDmg = wrkDmg
+			} else if v.Power() == tgt.Power() {
+				if v.init > tgt.init {
+					tgt = v
+					tgtDmg = wrkDmg
+				}
+			}
+		}
+		if Debug {
+			var tpTxt string
+			if a.tp == ArmyTypeImmune {
+				tpTxt = "Immune System"
+			} else {
+				tpTxt = "Infection"
+			}
+			fmt.Printf("%s group %d would deal defending group %d %d damage\n", tpTxt, a.id, tgt.id, tgtDmg)
+		}
+	}
+	if tgt != nil {
+		a.target = tgt
+		tgt.targettedBy = a
+	}
+}
+
+func (a *Army) CalculateDamage(b *Army) int {
+	if b.IsWeakTo(a.damageType) {
+		return a.Power() * 2
+	} else if b.IsImmuneTo(a.damageType) {
+		return 0
+	}
+	return a.Power()
+}
+
+func (a *Army) Damage(b *Army) int {
+	var unitsDefeated int
+	dmg := a.CalculateDamage(b)
+	for dmg > 0 {
+		dmg -= b.hp
+		if dmg > 0 && b.units > 0 {
+			b.units--
+			unitsDefeated++
+		}
+	}
+	b.targettedBy = nil
+	return unitsDefeated
+}
+
+func (a *Army) Fight() {
+	if a.target != nil {
+		var tpTxt string
+		if a.tp == ArmyTypeImmune {
+			tpTxt = "Immune System"
+		} else if a.tp == ArmyTypeInfection {
+			tpTxt = "Infection"
+		}
+		dmg := a.Damage(a.target)
+		if Debug {
+			fmt.Printf("%s group %d attacks defending group %d, killing %d units\n", tpTxt, a.id, a.target.id, dmg)
+		}
+	}
+}
+
+func (a Army) String() string {
+	ret := fmt.Sprintf("%d units each with %d hit points ", a.units, a.hp)
+	if len(a.weaknesses) > 0 {
+		ret = ret + fmt.Sprintf("(weaknesses: %s) ", a.weaknesses)
+	}
+	if len(a.immunities) > 0 {
+		ret = ret + fmt.Sprintf("(immunities: %s) ", a.immunities)
+	}
+	ret = ret + fmt.Sprintf("with an attack that does %d %s damage at initiative %d\n",
+		a.strength, a.damageType, a.init,
+	)
+	return ret
+}
+
 // Army Sorting
-type ByPower []Army
+type ByPower []*Army
+
 func (b ByPower) Len() int      { return len(b) }
 func (b ByPower) Swap(i, j int) { b[i], b[j] = b[j], b[i] }
-func (b ByPower) Less(i, j int) { b[i].Power() < b[j].Power() }
+func (b ByPower) Less(i, j int) bool {
+	if b[i].Power() == b[j].Power() {
+		return b[i].init < b[j].init
+	}
+	return b[i].Power() < b[j].Power()
+}

2018/day24/combat.go

@@ -1,10 +1,72 @@
 package main
 
+import (
+	"fmt"
+	"sort"
+)
+
+type Battle struct {
+	immune []*Army
+	infect []*Army
+}
+
+func NewBattle(immune, infect []*Army) *Battle {
+	return &Battle{
+		immune: immune,
+		infect: infect,
+	}
+}
+
+func (b *Battle) PrintStatus() {
+	fmt.Println("Immune System:")
+	for _, v := range b.immune {
+		fmt.Printf("Group %d contains %d units\n", v.id, v.units)
+	}
+	fmt.Println("Infection:")
+	for _, v := range b.infect {
+		fmt.Printf("Group %d contains %d units\n", v.id, v.units)
+	}
+}
+
 // All Battle Logic is in here
-func Battle(army1, army2 []Army) {
-  allCombatants = append(army1, army2...)
+func (b *Battle) Fight() {
+	allCombatants := append(b.immune, b.infect...)
 	sort.Sort(ByPower(allCombatants))
-  for _, v := range allCombatants {
-    fmt.Print("%d %d %d (%d)\n", v.tp, v.units, v.hp, v.Power())
+	for k := len(allCombatants) - 1; k >= 0; k-- {
+		b.FindTargetFor(allCombatants[k])
+	}
+	if Debug {
+		fmt.Println("")
+	}
+	for k := len(allCombatants) - 1; k >= 0; k-- {
+		allCombatants[k].Fight()
+	}
+	i := 0
+	for _, x := range b.immune {
+		if x.units > 0 {
+			b.immune[i] = x
+			i++
 		}
 	}
+	b.immune = b.immune[:i]
+	i = 0
+	for _, x := range b.infect {
+		if x.units > 0 {
+			b.infect[i] = x
+			i++
+		}
+	}
+	b.infect = b.infect[:i]
+}
+
+func (b *Battle) FindTargetFor(a *Army) {
+	if a.tp == ArmyTypeImmune {
+		a.FindTarget(b.infect)
+	} else if a.tp == ArmyTypeInfection {
+		a.FindTarget(b.immune)
+	}
+}
+
+func (b *Battle) IsOver() bool {
+	return len(b.immune) == 0 || len(b.infect) == 0
+}

2018/day24/day24.go

@@ -4,43 +4,50 @@ import (
 	"bufio"
 	"fmt"
 	"os"
-	"strings"
 )
 
 const (
-	ArmyTypeImmune = 1 << iota
-	ArmyTypeInfection
+	Debug = true
 )
 
 func main() {
 	inp := StdinToStringSlice()
 	immune, infect := ParseInput(inp)
-  for _, v := range immune {
-    fmt.Println("++ ", v.immunities)
-    fmt.Println("-- ", v.weaknesses)
+
+	b := NewBattle(immune, infect)
+	//for !b.IsOver() {
+	if Debug {
+		b.PrintStatus()
+		fmt.Println("")
 	}
-  _, _ = immune, infect
+	b.Fight()
+	//}
+
+	fmt.Println("")
+	fmt.Println("The battle is over!")
+	b.PrintStatus()
 }
 
-func ParseInput(inp []string) ([]Army, []Army) {
-	var immune, infection []Army
-	var tp int
+func ParseInput(inp []string) ([]*Army, []*Army) {
+	var immune, infection []*Army
+	var tp, id int
 	for _, v := range inp {
 		if v == "" {
 			continue
 		}
 		if v == "Immune System:" {
-			tp = ArmyTypeImmune
+			tp, id = ArmyTypeImmune, 0
 			continue
 		} else if v == "Infection:" {
-			tp = ArmyTypeInfection
+			tp, id = ArmyTypeInfection, 0
 			continue
 		}
+		id++
 		switch tp {
 		case ArmyTypeImmune:
-			immune = append(immune, *NewArmy(v, tp))
+			immune = append(immune, NewArmy(v, tp, id))
 		case ArmyTypeInfection:
-			infection = append(infection, *NewArmy(v, tp))
+			infection = append(infection, NewArmy(v, tp, id))
 		}
 	}
 	return immune, infection

2018/day24/testinput

@@ -0,0 +1,7 @@
+Immune System:
+17 units each with 5390 hit points (weak to radiation, bludgeoning) with an attack that does 4507 fire damage at initiative 2
+989 units each with 1274 hit points (immune to fire; weak to bludgeoning, slashing) with an attack that does 25 slashing damage at initiative 3
+
+Infection:
+801 units each with 4706 hit points (weak to radiation) with an attack that does 116 bludgeoning damage at initiative 1
+4485 units each with 2961 hit points (immune to radiation; weak to fire, cold) with an attack that does 12 slashing damage at initiative 4