leetcode--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 class Solution {
    /**This problem is a simple application of DP.<br>
     * ways[n] = ways[n - 1] + ways[n - 2].<br>
     * @author Averill Zheng
     * @version 2014-06-04
     * @since JDK 1.7
     *  
     */
    public int climbStairs(int n) {
        int differentWays = 0;
		if(n == 1)
			differentWays = 1;
		if(n == 2)
			differentWays = 2;
		if(n > 2){
			int[] ways = new int[n];
			ways[0] = 1;
			ways[1] = 2;
			for(int i = 2; i < n; ++i)
				ways[i] = ways[i - 1] +  ways[i - 2];
			differentWays = ways[n-1];
		}
		return differentWays;    
    }
}