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61 lines
990 B
61 lines
990 B
package main |
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import ( |
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"AoC2020/helper" |
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"errors" |
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"fmt" |
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"os" |
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"sort" |
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) |
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func main() { |
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args := os.Args[1:] |
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input, err := helper.GetInput(args[0]) |
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if err != nil { |
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fmt.Println(err) |
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} |
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fmt.Println(day1(input)) |
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fmt.Println(day1_part2(input)) |
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} |
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func day1(numbers []int) int { |
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goal := 2020 |
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sort.Ints(numbers) |
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p1 := 0 |
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p2 := len(numbers) - 1 |
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for { |
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if numbers[p1]+numbers[p2] < goal { |
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p1++ |
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} |
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if numbers[p1]+numbers[p2] > goal { |
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p2-- |
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} |
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if numbers[p1]+numbers[p2] == goal { |
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return numbers[p1] * numbers[p2] |
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} |
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} |
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} |
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func day1_part2(numbers []int) (int, error) { |
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goal := 2020 |
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sort.Ints(numbers) |
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for i, number := range numbers { |
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p1 := i + 1 |
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p2 := len(numbers) - 1 - i |
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for p1 < p2 { |
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if numbers[p1]+numbers[p2]+number < goal { |
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p1++ |
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} |
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if numbers[p1]+numbers[p2]+number > goal { |
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p2-- |
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} |
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if numbers[p1]+numbers[p2]+number == goal { |
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return numbers[p1] * numbers[p2] * number, nil |
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} |
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} |
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} |
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return 0, errors.New("No Triplet Found") |
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}
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