50 lines
911 B
Go
50 lines
911 B
Go
package dayone
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import (
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"advent-of-code/internal/registry"
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"os"
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"strconv"
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"strings"
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)
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func init() {
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registry.Register("2020D1", ParseInput, PartOne, PartTwo)
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}
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func ParseInput(filepath string) []int {
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content, _ := os.ReadFile(filepath)
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lines := strings.Fields(string(content))
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var data []int
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for _, line := range lines {
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num, _ := strconv.Atoi(line)
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data = append(data, num)
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}
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return data
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}
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func PartOne(data []int) int {
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seen := make(map[int]bool)
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for _, number := range data {
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complement := 2020 - number
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if seen[complement] {
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return number * complement
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}
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seen[number] = true
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}
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return 0
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}
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func PartTwo(data []int) int {
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seen := make(map[int]bool)
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for idx := range data {
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for _, number := range data[idx+1:] {
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complement := 2020 - data[idx] - number
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if seen[complement] {
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return complement * data[idx] * number
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}
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}
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seen[data[idx]] = true
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}
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return 0
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}
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