ClimbingStairs

Change-Id: I1dd45e00245c9ea207db9fdbf13934dda4a428ca

Author: applewjg

ClimbingStairs.java

@@ -0,0 +1,21 @@
+/*
+ Author:     King,[email protected]
+ Date:       Dec 25, 2014
+ Problem:    Climbing Stairs
+ Difficulty: Easy
+ Source:     https://oj.leetcode.com/problems/climbing-stairs/
+ Notes:
+ 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: Clime one step from last stair or clime 2 steps from the last last stair.
+ */
+public class Solution {
+    public int climbStairs(int n) {
+        int[] f = new int[n+1];
+        f[0] = 1; f[1] = 1;
+        for (int i = 2; i <= n; ++i)
+            f[i] = f[i-1] + f[i-2];
+        return f[n];
+    }
+}