add: climbing stairs solution

Author: JEONGBEOMKO

climbing-stairs/JEONGBEOMKO.java

@@ -0,0 +1,19 @@
+package week02.Climbing_stairs;
+
+class Solution {
+    public int climbStairs(int n) {
+
+        if (n == 1 || n == 2) {
+            return n;
+        }
+
+        int[] cases = new int[n + 1];
+        cases[1] = 1;
+        cases[2] = 2;
+        for (int i = 3; i <= n; i++) {
+            cases[i] = cases[i - 1] + cases[i - 2];
+        }
+
+        return cases[n];
+    }
+}