Code-Memo

Recursion

Go supports recursive functions like other Algol-family languages. Each call gets its own stack frame; deep recursion can overflow the stack — prefer iteration or a trampoline for very deep problems.

Factorial

func fact(n int) int {
	if n <= 1 {
		return 1
	}
	return n * fact(n-1)
}

Tree walk

type Node struct {
	Value int
	Left  *Node
	Right *Node
}

func (n *Node) Sum() int {
	if n == nil {
		return 0
	}
	return n.Value + n.Left.Sum() + n.Right.Sum()
}

Mutual recursion

func even(n int) bool {
	if n == 0 {
		return true
	}
	return odd(n - 1)
}

func odd(n int) bool {
	if n == 0 {
		return false
	}
	return even(n - 1)
}

Practical notes

• Tail-call optimization is not guaranteed; write loops when depth is unbounded.
• For divide-and-conquer on slices, pass indices to avoid copying sub-slices when performance matters.