77 lines
1.8 KiB
Odin
77 lines
1.8 KiB
Odin
package main
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import "core:math"
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import "core:slice"
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import "core:strconv"
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import "core:strings"
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import "core:bytes"
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import "core:fmt"
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import "core:os"
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import "../util"
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part_1 :: proc(lines: []string) {
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result: i64 = 0
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numbers := slice.clone_to_dynamic(
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slice.mapper(lines, proc(line: string) -> i64 {
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num, ok := strconv.parse_i64(line); assert(ok)
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return num
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}))
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slice.sort(numbers[:])
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inject_at(&numbers, 0, 0)
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append(&numbers, slice.last(numbers[:]) + 3)
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ones: i64 = 0
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threes: i64 = 0
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for _, idx in numbers[:len(numbers)-1] {
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switch numbers[idx+1] - numbers[idx] {
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case 1: ones += 1
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case 3: threes += 1
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}
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}
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result = ones * threes
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fmt.printfln("Part 1: %d", ones * threes)
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}
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part_2 :: proc(lines: []string) {
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result: i64 = 1
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numbers := slice.clone_to_dynamic(
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slice.mapper(lines, proc(line: string) -> i64 {
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num, ok := strconv.parse_i64(line); assert(ok)
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return num
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}))
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slice.sort(numbers[:])
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inject_at(&numbers, 0, 0)
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append(&numbers, slice.last(numbers[:]) + 3)
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combinations := make([]i64, len(numbers))
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combinations[len(combinations)-1] = 1
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for idx1 := len(numbers) - 2 ; idx1 >= 0; idx1 -= 1 {
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ways: i64 = 0
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for idx2 := idx1 + 1; idx2 <= idx1 + 3; idx2 += 1 {
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if idx2 >= len(numbers) do continue
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if numbers[idx2] - numbers[idx1] <= 3 do ways += combinations[idx2]
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}
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combinations[idx1] = ways
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}
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result = combinations[0]
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fmt.printfln("Part 2: %d", result)
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}
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main :: proc() {
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context.allocator = context.temp_allocator
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defer free_all(context.temp_allocator)
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INPUT :: #load("input.txt", string)
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lines := strings.split(INPUT, "\n")
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lines = lines[:len(lines)-1]
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part_1(lines)
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part_2(lines)
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}
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