Solution for House Robber #264

Author: dohyeon2

house-robber/dohyeon2.java

@@ -0,0 +1,30 @@
+class Solution {
+    public int rob(int[] nums) {
+        // Dynamic Planning
+        // Time Complexity: O(n)
+        // Space Complexity: O(n) for the dp array
+        // When applying DP, it is important to define the accumulated state clearly.
+
+        if (nums.length == 1) {
+            return nums[0];
+        }
+
+        // The state of dp is maximum amount of robbery at i
+        int[] dp = new int[nums.length];
+
+        dp[0] = nums[0];
+        dp[1] = Math.max(nums[0], nums[1]);
+
+        for (int i = 2; i < nums.length; i++) {
+            dp[i] = Math.max(
+                    // If we skip the current house,
+                    // we can take the maximum amount of robbery at i - 1
+                    dp[i - 1],
+                    // If we rob the current house, we cannot rob the previous house
+                    // so we can take the maximum amount of robbery at i - 2
+                    dp[i - 2] + nums[i]);
+        }
+
+        return dp[nums.length - 1];
+    }
+}