39 lines
580 B
Go
39 lines
580 B
Go
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package main
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import (
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"fmt"
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"os"
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)
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func main() {
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step := os.Args[1]
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indexMap := make(map[int]int)
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indexMap[0] = 0
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indexMap[14] = 1
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indexMap[1] = 2
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indexMap[3] = 3
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indexMap[7] = 4
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last := 9
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loops := 0
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switch step {
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case "1":
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loops = 2020
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case "2":
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loops = 30000000
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}
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for i := 5; i < loops-1; i++ {
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if x, ok := indexMap[last]; ok {
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indexMap[last] = i
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// fmt.Printf("%d was last seen %d ago\n", last, i-x)
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last = i - x
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} else {
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indexMap[last] = i
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// fmt.Printf("%d has not been seen before\n", last)
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last = 0
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}
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}
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fmt.Println(last)
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}
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