advent_of_code_2025/9/solve_1.go

package main

import (
	"bufio"
	"fmt"
	"math"
	"os"
	"strconv"
	"strings"
)

func main() {
	fmt.Println("Advent of Code 2025 - Day 9 - Part 1")
	f,_:= os.Open("9/input")
	defer f.Close()
	scanner:=bufio.NewScanner(f)

	var red_walls [][]int
	for scanner.Scan(){
		line:= scanner.Text()
		line_sp := strings.Split(line, ",")
		x,_:= strconv.Atoi(line_sp[0])
		y,_:= strconv.Atoi(line_sp[1])
		red_walls = append(red_walls, []int{x,y})
	}

	res := 0
	for i:= range red_walls {
		w1:= red_walls[i]
		for j:= i+1; j < len(red_walls); j++{
			w2:= red_walls[j]
			area := calculate_area(w1,w2)
			if area > res {
				res = area
			}
			}
	}
	fmt.Println(res)
}

func calculate_area(w1,w2 []int) int{
	dx, dy := int(math.Abs(float64(w1[0]-w2[0]))), int(math.Abs(float64(w1[1]-w2[1])))
	return (dx+1) * (dy+1)
}