70_new.cpp

Linvoker · Feb 27, 2019 · 8f45b29 · 8f45b29
1 parent ff1398e
commit 8f45b29
Showing 1 changed file with 16 additions and 0 deletions.
diff --git a/70_new.cpp b/70_new.cpp
@@ -0,0 +1,16 @@
+class Solution {
+public:
+    int climbStairs(int n) {
+        vector<int> table(n + 1, -1);
+        return helper(n, table);
+    }
+    int helper(int n, vector<int> &table) {
+        if (n <= 1) {
+            return 1;
+        }
+        if (table[n] != -1) {
+            return table[n];
+        }
+        return table[n] = helper(n - 1, table) + helper(n - 2, table);
+    }
+};