advent_of_code_2025/3/solve_1.go

package main

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


func main() {
	fmt.Println("Advent of Code 2025 - Day 3 - Part 1")
	f,_:= os.Open("3/input")
	defer f.Close()
	scanner := bufio.NewScanner(f)
	var res int;
	for scanner.Scan(){
		bank := scanner.Text()
		max_volt,_ := max_voltage(bank)		
		res += max_volt
	}
	fmt.Println(res)
}


func max_voltage(bank string) (int, error){
	max1, max2 := byte('0'),byte('0')
	i_max1, i_max2:= -1,-1
	var result string
	
	for i:= 0; i < len(bank); i++{
		if bank[i] > max1{
			max1,i_max1 = bank[i],i
		}
	}
	
	for i:= i_max1+1; i < len(bank); i++{
		if bank[i] > max2{
			max2,i_max2 = bank[i],i
		}
	}

	if i_max2 == -1 {
		for i:= 0; i < len(bank); i++{
			if bank[i] > max2 && i != i_max1{
				max2,i_max2 = bank[i],i
			}
		}
	}

	if i_max2 > i_max1 {
		result = string([]byte{max1, max2})
	} else {
		result = string([]byte{max2, max1})
	}
	
	return strconv.Atoi(result)
}