solution 70 and update README

Author: xiao2shiqi

README.md

@@ -45,7 +45,7 @@ LeetCode
 |100|[Same Tree](https://leetcode-cn.com/problems/same-tree/)| [Java](https://github.com/xiao2shiqi/leetcode/blob/master/src/main/java/Solution100.java) | Easy
 |88|[Merge Sorted Array](https://leetcode-cn.com/problems/merge-sorted-array/)| [Java](https://github.com/xiao2shiqi/leetcode/blob/master/src/main/java/Solution88.java) | Easy
 |83|[Remove Duplicates from Sorted List](https://leetcode-cn.com/problems/remove-duplicates-from-sorted-list/)| [Java](https://github.com/xiao2shiqi/leetcode/blob/master/src/main/java/Solution83.java) | Easy
-|70|[Climbing Stairs](https://leetcode-cn.com/problems/climbing-stairs/)| [Java](https://github.com/xiao2shiqi/leetcode/blob/master/src/main/java/Solution70.java) | Easy
+|70|[Climbing Stairs](https://leetcode-cn.com/problems/climbing-stairs/)| [Java](https://github.com/xiao2shiqi/leetcode/blob/master/src/main/java/Solution70.java), [Ruby](https://github.com/xiao2shiqi/leetcode/blob/master/ruby/solution70.rb) | Easy
 |67|[Add Binary](https://leetcode-cn.com/problems/add-binary/)| [Java](https://github.com/xiao2shiqi/leetcode/blob/master/src/main/java/Solution67.java) | Easy
 |66|[Plus One](https://leetcode-cn.com/problems/plus-one/)| [Java](https://github.com/xiao2shiqi/leetcode/blob/master/src/main/java/Solution66.java), [Ruby](https://github.com/xiao2shiqi/leetcode/blob/master/ruby/solution66.rb) | Easy
 |58|[Length of Last Word](https://leetcode-cn.com/problems/length-of-last-word/)| [Java](https://github.com/xiao2shiqi/leetcode/blob/master/src/main/java/Solution58.java), [Ruby](https://github.com/xiao2shiqi/leetcode/blob/master/ruby/solution58.rb)  | Easy
@@ -59,6 +59,6 @@ LeetCode
 |20|[Valid Parentheses](https://leetcode-cn.com/problems/valid-parentheses/)| [Java](https://github.com/xiao2shiqi/leetcode/blob/master/src/main/java/Solution20.java), [Ruby](https://github.com/xiao2shiqi/leetcode/blob/master/ruby/solution20.rb) | Easy
 |14|[Longest Common Prefix](https://leetcode-cn.com/problems/longest-common-prefix/)| [Java](https://github.com/xiao2shiqi/leetcode/blob/master/src/main/java/Solution14.java), [Ruby](https://github.com/xiao2shiqi/leetcode/blob/master/ruby/solution14.rb) | Easy
 |13|[Roman to Integer](https://leetcode-cn.com/problems/roman-to-integer/)| [Java](https://github.com/xiao2shiqi/leetcode/blob/master/src/main/java/Solution13.java), [Ruby](https://github.com/xiao2shiqi/leetcode/blob/master/ruby/solution13.rb) | Easy
-|9|[Palindrome Number](https://leetcode-cn.com/problems/palindrome-number/)| [Java](https://github.com/xiao2shiqi/leetcode/blob/master/src/main/java/Solution9.java), [Ruby](https://github.com/xiao2shiqi/leetcode/blob/master/ruby/solution9.rb) | Easy
+|9|[Palindrome Number](https://leetcode-cn.com/problems/palindrome-number/)| [Java](https://github.com/xiao2shiqi/leetcode/blob/master/src/main/java/Solution9.java), [Ruby](https://github.com/xiao2shiqi/leetcode/blob/master/ruby/solution9.rb), [Go](https://github.com/xiao2shiqi/leetcode/blob/master/go/9-solution.go) | Easy
 |7|[Reverse Integer](https://leetcode-cn.com/problems/reverse-integer/)| [Java](https://github.com/xiao2shiqi/leetcode/blob/master/src/main/java/Solution7.java), [Ruby](https://github.com/xiao2shiqi/leetcode/blob/master/ruby/solution7.rb), [Go](https://github.com/xiao2shiqi/leetcode/blob/master/go/7-solution.go)  | Easy
 |1|[Two Sum](https://leetcode-cn.com/problems/two-sum/)| [Java](https://github.com/xiao2shiqi/leetcode/blob/master/src/main/java/Solution1.java), [Ruby](https://github.com/xiao2shiqi/leetcode/blob/master/ruby/solution1.rb), [Go](https://github.com/xiao2shiqi/leetcode/blob/master/go/1-solution.go) | Easy

ruby/solution70.rb

@@ -0,0 +1,26 @@
+=begin
+LC#70. Climbing Stairs https://leetcode-cn.com/problems/climbing-stairs/
+思路：
+刚开始拿到题，觉得是递归的解法，尝试用递归，发现太多重复运算
+Google看到可以用动态规划的思想来解决
+既保存每次解法的结果到r[i]中
+每上一层阶梯，就调用上次的结果来计算 
+=end
+
+# @param {Integer} n
+# @return {Integer}
+def climb_stairs(n)
+  return n if [1, 2, 3].include?(n)
+  r = []
+  r[1] = 1
+  r[2] = 2
+  i = 3
+  while i <= n do 
+    r[i] = r[i - 1] + r[i - 2]
+    i += 1
+  end
+  r[n]
+end
+
+res = climb_stairs(10)
+p "res: #{res}"