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46 lines
833 B
Go
46 lines
833 B
Go
package two
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import (
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"bytes"
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"math"
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log "github.com/sirupsen/logrus"
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"github.com/onyx-and-iris/aoc2024/day-13/internal/util"
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)
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const augment = 10e12
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func Solve(buf []byte) (int, error) {
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r := bytes.NewReader(buf)
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machines, err := util.ParseLines(r)
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if err != nil {
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return 0, err
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}
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var total int
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for _, m := range machines {
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m.Prize.X += augment
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m.Prize.Y += augment
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denominator := ((m.A.X * m.B.Y) - (m.B.X * m.A.Y))
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a_numerator := ((m.Prize.X * m.B.Y) - (m.Prize.Y * m.B.X))
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b_numerator := ((m.Prize.Y * m.A.X) - (m.Prize.X * m.A.Y))
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a := float64(a_numerator) / float64(denominator)
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b := float64(b_numerator) / float64(denominator)
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if a != math.Round(a) || b != math.Round(b) {
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continue
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}
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log.Debug(a, b)
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if a > 0 && b > 0 {
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total += 3*int(a) + int(b)
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}
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}
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return total, nil
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}
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