Climbing Stairs

ClimbingStairs.java

/**
 * 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 class Solution {
    public int climbStairs(int n) {
		int[] arr = new int[n + 1];
		arr[0] = 1;
		arr[1] = 1;
		for (int i = 2; i <= n; i++) {
			arr[i] = arr[i - 1] + arr[i - 2];
		}
		return arr[n];
	}

}