01. Day of Week

package main
import "fmt"

func main() {
    var num int
    fmt.Scanln(&num)

    if (num == 1) {
        fmt.Println("Monday")
    } else if (num == 2) {
        fmt.Println("Tuesday")
    } else if (num == 3) {
        fmt.Println("Wednesday")
    } else if (num == 4) {
        fmt.Println("Thursday")
    } else if (num == 5) {
        fmt.Println("Friday")
    } else if (num == 6) {
        fmt.Println("Saturday")
    } else if (num == 7) {
        fmt.Println("Sunday")
    } else {
        fmt.Println("Error")
    }
}

ИЛИ:

package main
import "fmt"

func main() {
    var num int
    fmt.Scanln(&num)

    switch num {
    case 1:
        fmt.Println("Monday")
    case 2:
        fmt.Println("Tuesday")
    case 3:
        fmt.Println("Wednesday")
    case 4:
        fmt.Println("Thursday")
    case 5:
        fmt.Println("Friday")
    case 6:
        fmt.Println("Saturday")
    case 7:
        fmt.Println("Sunday")
    default:
        fmt.Println("Error")
    }
}

Решение с масив:

package main
import "fmt"

func main() {
    var num int
    fmt.Scanln(&num)

    var dayOfWeek = []string {"Error", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"}

    if(num > 0 && num < len(dayOfWeek)) {
        fmt.Println(dayOfWeek[num])
    } else {
        fmt.Println(dayOfWeek[0])
    }
}