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 {
    public int climbStairs(int n) 
    {
        int[] count = new int[n+1];
        if(n<=1)return n;
        count[0]=1;   //注意这个得赋值为1，之后才可以正常运行
        count[1]=1;
        
        for(int i=2;i<=n;i++)
           {
               count[i]=count[i-1]+count[i-2];
           }
           
        return count[n];
        
    }
}