48 lines
856 B
Go
48 lines
856 B
Go
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package main
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import (
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"fmt"
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"strings"
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h "git.bullercodeworks.com/brian/adventofcode/helpers"
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)
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func main() {
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fmt.Println("# Day 15")
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inp := h.StdinToString()
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fmt.Println("## Part 1")
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dumbFind(inp, 2020)
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fmt.Println("## Part 2")
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dumbFind(inp, 30000000)
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}
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func dumbFind(inp string, num int) {
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start := strings.Split(inp, ",")
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rem := make(map[int][]int)
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turn := 1
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var last int
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for k := range start {
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last = h.Atoi(start[k])
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rem[last] = []int{turn}
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turn++
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}
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for turn <= num {
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last = speakNext(last, turn, &rem)
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turn++
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}
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fmt.Println("Answer:", last)
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}
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func speakNext(prev int, turn int, rem *map[int][]int) int {
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wrk := *rem
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if len(wrk[prev]) == 1 {
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wrk[0] = append(wrk[0], turn)
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return 0
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} else {
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last := wrk[prev][len(wrk[prev])-2]
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diff := (turn - 1) - last
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wrk[diff] = append(wrk[diff], turn)
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return diff
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}
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}
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