70. Climbing Stairs

Author: TonyKim9401

climbing-stairs/TonyKim9401.java

@@ -0,0 +1,15 @@
+class Solution {
+    public int climbStairs(int n) {
+        // Time complexity: O(n);
+        // Space complexity: O(n);
+        int[] dp = new int[n+1];
+
+        if (n >= 1) dp[1] = 1;
+        if (n >= 2) dp[2] = 2;
+
+        for (int i = 3; i <= n; i++) {
+            dp[i] = dp[i-1] + dp[i-2];
+        }
+        return dp[n];
+    }
+}