递归而不是循环[关闭]

Question

I'm new in Go programming, so how to implement recursion instead of a for loop in this code?

package main

import (
    "fmt"
)

func main() {
    var n int
    fmt.Scan(&n)
    set(n)
}

func set(n int) {
    a := make([]int, n)
    for i := 0; i < n; i++ {
        fmt.Scan(&a[i])
    }
    fmt.Println(a)
}

Answer 1

I am not sure what you want to be recursive. But as I understand your question as changing a for-loop into a recursion, I made it into a tail recursion in a closure, in a functional programing style.

func set(n int) {
    a := make([]int, n)
    var setRecursive func(int) // declare a function variable, which take an int as param.
    setRecursive = func(i int) { // set the function in closure, so a and n is available to it.
        if i == 0 { // end point of the recursion, return.
            return
        }
        Scan(&a[n-i]) // Use fmt.Scan out of playground
        setRecursive(i - 1) // tail recursion.
    }
    setRecursive(n) // call the function, start the recursion.
    fmt.Println(a)
}

If you want the matter simpler, you can remove the closure part and move the line Scan(&a[n-i]) behind the line setRecursive(n), Like below:

func SetRecursive(a []int, n int) {
    if n==0 {
        return
    }

    SetRecursive(a,n-1) // recurse first, so we can scan in the right order.
    Scan(&a[n-1])
}

Playground: https://play.golang.org/p/0io190tyviE