Create 70. Climbing Stairs.java

Author: rising0raj

70. Climbing Stairs.java

@@ -0,0 +1,24 @@
+// Runtime    0ms
+// Beats      100.00%
+
+// Memory     40.35MB
+// Beats      23.54%
+
+
+class Solution {
+    private int[] memo = new int[46];
+
+    public int climbStairs(int n) {
+        if (n <= 0) return 0;
+        if (n == 1 || n == 2 || n == 3) return n;
+
+        if (memo[n] != 0) {
+            return memo[n];
+        }
+
+        int ways = climbStairs(n - 1) + climbStairs(n - 2);
+        memo[n] = ways;
+
+        return ways;
+    }
+}