Advent of Code 2020 Day 1

package main

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

func prepare() []int {
    f, err := os.Open("input.txt")
    if err != nil {
        log.Println(err)
    }
    defer func() {
        err = f.Close()
        if err != nil {
            log.Println(err)
        }
    }()

    b, err := ioutil.ReadAll(f)
    if err != nil {
        log.Println(err)
    }

    s := strings.Split(string(b), "\r\n")

    var z int
    var q []int
    for i := range s {
        z, err = strconv.Atoi(s[i])
        if err != nil {
            log.Println(err)
        }
        q = append(q, z)
    }
    return q
}

func main(){

    q := prepare()
    solution := func() int {
        l := 0
        t := 0
        for c := range q {
            for l < len(q) {
                for t < len(q) {
                    if q[c] + q[l] + q[t] == 2020 {
                        return q[c] * q[l] * q[t]
                    }
                    t++
                }
                l++
                t = 0
            }
            l = 0
        }
        return 0
    }

    log.Println(solution())

}