LeetCode8|爬楼梯

输入：2
输出：2
解释：有两种方法可以爬到楼顶。
1.  1 阶 + 1 阶
2.  2 阶

public class ClimbStairsTest {    
    public static void main(String[] args) {        
        int n = 2;        
        int stairs = climbStairs(n);        
        System.out.println("stairs = " + stairs);    
        }
    public static int climbStairs(int n) {        
        if (n == 0) {            
            return 1;        
        }        
        if (n == 1) {            
            return 1;        
        }        
        int[] dp = new int[n + 1];        
        dp[0] = 1;        
        dp[1] = 1;        
        for (int i = 2; i <= n; i++) {            
            dp[i] = dp[i - 1] + dp[i - 2];        
        }        
        return dp[n];    }}