File(s) Modified: 0198-houses-robber.java

winfred-lu · winfred-lu · commit 87fa0ee02d45 · 2023-08-24T16:30:31.000+08:00
Language(s) Used: java Submission URL: https://leetcode.com/problems/house-robber/submissions/1030302644/
diff --git a/java/0198-house-robber.java b/java/0198-house-robber.java
@@ -32,4 +32,18 @@ public int robDP(int[] nums) {
         }
         return dp[nums.length - 1];
     }
+
+    // DP with O(1) space
+    public int robDP2(int[] nums) {
+        if (nums == null || nums.length == 0) return 0;
+
+        int dp0 = 0, dp1 = 0, curr;
+
+        for (int i = 0; i < nums.length; i++) {
+            curr = Math.max(dp0 + nums[i], dp1);
+            dp0 = dp1;
+            dp1 = curr;
+        }
+        return Math.max(dp0, dp1);
+    }
 }

Original file line number	Diff line number	Diff line change
`@@ -32,4 +32,18 @@ public int robDP(int[] nums) {`
`32`	`32`	`}`
`33`	`33`	`return dp[nums.length - 1];`
`34`	`34`	`}`
	`35`	`+`
	`36`	`+ // DP with O(1) space`
	`37`	`+ public int robDP2(int[] nums) {`
	`38`	`+ if (nums == null \|\| nums.length == 0) return 0;`
	`39`	`+`
	`40`	`+ int dp0 = 0, dp1 = 0, curr;`
	`41`	`+`
	`42`	`+ for (int i = 0; i < nums.length; i++) {`
	`43`	`+ curr = Math.max(dp0 + nums[i], dp1);`
	`44`	`+ dp0 = dp1;`
	`45`	`+ dp1 = curr;`
	`46`	`+ }`
	`47`	`+ return Math.max(dp0, dp1);`
	`48`	`+ }`
`35`	`49`	`}`