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?

Solution:

  1. public class Solution {
  2.   public int climbStairs(int n) {
  3.     if (n == 0)
  4.       return 0;
  6.     if (n == 1)
  7.       return 1;
  9.     int[] dp = new int[n + 1];
  11.     dp[0] = 1; dp[1] = 1;
  13.     for (int i = 2; i <= n; i++) {
  14.       dp[i] = dp[i - 1] + dp[i - 2];
  15.     }
  17.     return dp[n];
  18.   }
  19. }