refactor 198

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_198.java

@@ -2,33 +2,45 @@
 
 /**198. House Robber
 
-You are a professional robber planning to rob houses along a street.
+ You are a professional robber planning to rob houses along a street.
  Each house has a certain amount of money stashed,
- the only constraint stopping you from robbing each of them is that adjacent houses have security system connected and
- it will automatically contact the police if two adjacent houses were broken into on the same night.
-
-Given a list of non-negative integers representing the amount of money of each house,
+ the only constraint stopping you from robbing each of them is that adjacent houses have security
+ system connected and it will automatically contact the police if two adjacent houses were broken into on the same night.
+ Given a list of non-negative integers representing the amount of money of each house,
  determine the maximum amount of money you can rob tonight without alerting the police.
+
+ Example 1:
+ Input: [1,2,3,1]
+ Output: 4
+ Explanation: Rob house 1 (money = 1) and then rob house 3 (money = 3).
+ Total amount you can rob = 1 + 3 = 4.
+
+ Example 2:
+ Input: [2,7,9,3,1]
+ Output: 12
+ Explanation: Rob house 1 (money = 2), rob house 3 (money = 9) and rob house 5 (money = 1).
+ Total amount you can rob = 2 + 9 + 1 = 12.
  */
 public class _198 {
 
-    public int rob(int[] nums) {
-        if (nums == null || nums.length == 0) {
-            return 0;
-        }
-        if (nums.length == 1) {
-            return nums[0];
+    public static class Solution1 {
+        public int rob(int[] nums) {
+            if (nums == null || nums.length == 0) {
+                return 0;
+            }
+            if (nums.length == 1) {
+                return nums[0];
+            }
+            if (nums.length == 2) {
+                return Math.max(nums[0], nums[1]);
+            }
+            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(dp[i - 2] + nums[i], dp[i - 1]);
+            }
+            return dp[nums.length - 1];
         }
-        if (nums.length == 2) {
-            return Math.max(nums[0], nums[1]);
-        }
-        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(dp[i - 2] + nums[i], dp[i - 1]);
-        }
-        return dp[nums.length - 1];
     }
-
 }