CODE 62: Climbing Stairs

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?

public int climbStairs(int n) {// Note: The Solution object is instantiated only once and is reused by// each test case.if (n <= 0) {return 0;} else if (1 == n) {return 1;} else if (2 == n) {return 2;}int[] ways = new int[n + 1];ways[1] = 1;ways[2] = 2;for (int i = 3; i <= n; i++) {ways[i] = ways[i - 1] + ways[i - 2];}return ways[n];}