feat: week02 climbing-stairs

Author: std-freejia

climbing-stairs/std-freejia.java

@@ -0,0 +1,14 @@
+class Solution {
+    public int climbStairs(int n) {
+        int[] dp = new int [n + 1];
+        
+        if (n == 1) return 1;
+        dp[1] = 1;  
+        dp[2] = 2;
+
+        for (int i = 3; i <= n; i++) {
+            dp[i] = dp[i - 1] + dp[i - 2];
+        }
+        return dp[n];
+    }
+}