2024/day1/puzzle2.go
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package main
import (
"bufio"
"fmt"
"os"
"slices"
"strconv"
"strings"
)
func main() {
var left []int
var right []int
file, _ := os.Open("input1.txt")
defer file.Close()
scanner := bufio.NewScanner(file)
for scanner.Scan() {
line := scanner.Text()
fields := strings.Split(line, " ")
l, _ := strconv.Atoi(fields[0])
left = append(left, l)
r, _ := strconv.Atoi(fields[1])
right = append(right, r)
slices.Sort(left)
slices.Sort(right)
}
var total int
for i := range left {
d := similarity(left[i], right)
total += d
}
fmt.Println(total)
}
// calculate similarity score based on
// how many times n appears in the list
func similarity(n int, list []int) int {
count := 0
for _, l := range list {
if n == l {
count++
}
}
return n * count
}