https://leetcode.com/problems/climbing-stairs/submissions/

climbing-stairs-v2.go

var memo map[int]int
func init(){
	memo = make(map[int]int)
	memo[1] = 1
	memo[2] = 2
}

func climbStairs(n int) int {
	if v, ok := memo[n]; ok {
		return v
	}
	memo[n] = climbStairs(n-1) + climbStairs(n-2)
	return memo[n]
}

climbing-stairs.go

func climbStairs(n int) int {
	if n == 1 {
		return 1
	} else if n == 2 {
		return 2
	}
	memo := make(map[int]int, n)
	memo[1] = 1
	memo[2] = 2
	return solve(n, memo)
}

func solve(n int, memo map[int]int) int {
	if v, ok := memo[n]; ok {
		return v
	}
	memo[n] = solve(n-1, memo) + solve(n-2, memo)
	return memo[n]
}