main.go

package main

import "fmt"

// You are climbing a stair case. It takes n steps to reach to the top.

// Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?
//
// Note: Given n will be a positive integer.
//
//
// Example 1:
//
// Input: 2
// Output:  2
// Explanation:  There are two ways to climb to the top.
//
// 1. 1 step + 1 step
// 2. 2 steps
// Example 2:
//
// Input: 3
// Output:  3
// Explanation:  There are three ways to climb to the top.
//
// 1. 1 step + 1 step + 1 step
// 2. 1 step + 2 steps
// 3. 2 steps + 1 step

func climbStairs(n int) int {
	a, b := 1, 1
	for i := 1; i < n; i++ {
		a, b = b, a+b
	}
	return b
}

func main() {
	fmt.Println(climbStairs(0))
	fmt.Println(climbStairs(1))

	fmt.Println(climbStairs(2))
	fmt.Println(climbStairs(3))
	fmt.Println(climbStairs(4))
}