day24p1

day24p1/solution.go

@@ -0,0 +1,89 @@
+package day24p1
+
+import (
+	"fmt"
+	"io"
+	"sort"
+
+	"aoc/utils"
+)
+
+type Gate struct {
+	Op    string
+	Left  string
+	Right string
+	Dest  string
+}
+
+func Solve(r io.Reader) any {
+	lines := utils.ReadLines(r)
+	wires := make(map[string]byte)
+	gates := make(map[Gate]bool)
+
+	wireDecs := true
+
+	for _, line := range lines {
+		if line == "" {
+			wireDecs = false
+			continue
+		} else if wireDecs {
+			var wire string
+			var val byte
+			if _, err := fmt.Sscanf(line, "%3s: %d", &wire, &val); err != nil {
+				panic(err)
+			}
+			wires[wire] = val
+		} else {
+			var g Gate
+			if _, err := fmt.Sscanf(line, "%s %s %s -> %s", &g.Left, &g.Op, &g.Right, &g.Dest); err != nil {
+				panic(err)
+			}
+			gates[g] = false
+		}
+	}
+
+	for len(gates) > 0 {
+		for g := range gates {
+			if g.Left != "" {
+				if _, ok := wires[g.Left]; !ok {
+					continue
+				}
+			}
+			if g.Right != "" {
+				if _, ok := wires[g.Right]; !ok {
+					continue
+				}
+			}
+			switch g.Op {
+			case "AND":
+				wires[g.Dest] = wires[g.Left] & wires[g.Right]
+			case "OR":
+				wires[g.Dest] = wires[g.Left] | wires[g.Right]
+			case "XOR":
+				wires[g.Dest] = wires[g.Left] ^ wires[g.Right]
+			}
+			delete(gates, g)
+		}
+	}
+
+	return produceResult(wires)
+}
+
+func produceResult(wires map[string]byte) int {
+	var keys []string
+	for k := range wires {
+		if k[0] == 'z' {
+			keys = append(keys, k)
+		}
+	}
+
+	sort.Strings(keys)
+
+	var result int
+	for i, k := range keys {
+		if wires[k] == 1 {
+			result |= 1 << i
+		}
+	}
+	return result
+}

day24p1/solution_test.go

@@ -0,0 +1,79 @@
+package day24p1
+
+import (
+	"strings"
+	"testing"
+
+	"aoc/utils"
+)
+
+var testInput = `x00: 1
+x01: 0
+x02: 1
+x03: 1
+x04: 0
+y00: 1
+y01: 1
+y02: 1
+y03: 1
+y04: 1
+
+ntg XOR fgs -> mjb
+y02 OR x01 -> tnw
+kwq OR kpj -> z05
+x00 OR x03 -> fst
+tgd XOR rvg -> z01
+vdt OR tnw -> bfw
+bfw AND frj -> z10
+ffh OR nrd -> bqk
+y00 AND y03 -> djm
+y03 OR y00 -> psh
+bqk OR frj -> z08
+tnw OR fst -> frj
+gnj AND tgd -> z11
+bfw XOR mjb -> z00
+x03 OR x00 -> vdt
+gnj AND wpb -> z02
+x04 AND y00 -> kjc
+djm OR pbm -> qhw
+nrd AND vdt -> hwm
+kjc AND fst -> rvg
+y04 OR y02 -> fgs
+y01 AND x02 -> pbm
+ntg OR kjc -> kwq
+psh XOR fgs -> tgd
+qhw XOR tgd -> z09
+pbm OR djm -> kpj
+x03 XOR y03 -> ffh
+x00 XOR y04 -> ntg
+bfw OR bqk -> z06
+nrd XOR fgs -> wpb
+frj XOR qhw -> z04
+bqk OR frj -> z07
+y03 OR x01 -> nrd
+hwm AND bqk -> z03
+tgd XOR rvg -> z12
+tnw OR pbm -> gnj`
+
+func TestSolve(t *testing.T) {
+	tests := []struct {
+		input  string
+		answer int
+	}{
+		{testInput, 2024},
+	}
+
+	if testing.Verbose() {
+		utils.Verbose = true
+	}
+
+	for _, test := range tests {
+		r := strings.NewReader(test.input)
+
+		result := Solve(r).(int)
+
+		if result != test.answer {
+			t.Errorf("Expected %d, got %d", test.answer, result)
+		}
+	}
+}