Problem #13

Problem link
Solution:

package main

import (
    "io/ioutil"
    "strconv"
    "strings"
)

func main() {
    fileBuf, err := ioutil.ReadFile("013_input.txt")
    if err != nil {
        panic(err.String())
    }
    fileStr := string(fileBuf)
    lines := strings.Split(fileStr, "\n", 100)
    result := ""
    carryout, digit := 0, 0
    for i := 49; i >= 0; i-- {
        sum := carryout
        for j := range lines {
            num, _ := strconv.Atoi(string(lines[j][i]))
            sum += num
        }
        digit = sum % 10
        carryout = sum / 10
        result = strconv.Itoa(digit) + result
    }
    result = strconv.Itoa(carryout) + result
    println(result[0:10])
}

Result: 5537376230
Time: 0m0.010s