73 lines
1.5 KiB
Go
73 lines
1.5 KiB
Go
package dayseven
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import (
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"os"
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"strconv"
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"strings"
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"advent-of-code/internal/registry"
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)
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func init() {
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registry.Register("2015D7", ParseInput, PartOne, PartTwo)
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}
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func ParseInput(filepath string) map[string]string {
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content, _ := os.ReadFile(filepath)
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instructions := make(map[string]string)
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for _, line := range strings.Split(string(content), "\n") {
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if parts := strings.Split(line, " -> "); len(parts) == 2 {
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instructions[parts[1]] = parts[0]
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}
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}
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return instructions
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}
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func evaluateWire(wire string, instructions map[string]string) uint16 {
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cache := make(map[string]uint16)
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var evaluate func(string) uint16
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evaluate = func(wire string) uint16 {
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if value, ok := cache[wire]; ok {
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return value
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}
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if num, err := strconv.Atoi(wire); err == nil {
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return uint16(num)
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}
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expression, exists := instructions[wire]
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if !exists {
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return 0
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}
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parts := strings.Fields(expression)
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var result uint16
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switch {
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case len(parts) == 1:
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result = evaluate(parts[0])
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case parts[0] == "NOT":
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result = ^evaluate(parts[1])
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default:
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left, right := evaluate(parts[0]), evaluate(parts[2])
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switch parts[1] {
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case "AND":
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result = left & right
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case "OR":
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result = left | right
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case "LSHIFT":
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result = left << right
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case "RSHIFT":
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result = left >> right
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}
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}
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cache[wire] = result
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return result
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}
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return evaluate(wire)
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}
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func PartOne(instructions map[string]string) int {
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return int(evaluateWire("a", instructions))
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}
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func PartTwo(instructions map[string]string) int {
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return 0
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}
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