70. 爬楼梯

Author: geekidentity

src/main/java/com/geekidentity/leetcode/n0070/ClimbStairs.java

@@ -0,0 +1,20 @@
+package com.geekidentity.leetcode.n0070;
+
+/**
+ * 70. 爬楼梯
+ * https://leetcode-cn.com/problems/climbing-stairs/
+ * 计算机只会运行判断和简单重复性问题，因此要找最近重复子问题
+ */
+public class ClimbStairs {
+
+    public int climbStairs(int n) {
+        if (n <= 2) return n;
+        int a = 1, b = 2, c = 3;
+        for (int i = 3; i <= n; i++) {
+            c = a + b;
+            a = b;
+            b = c;
+        }
+        return c;
+    }
+}