Create MaxArraySum.java

Author: Foxeyyy

MaxArraySum.java

@@ -0,0 +1,57 @@
+import java.io.*;
+import java.math.*;
+import java.security.*;
+import java.text.*;
+import java.util.*;
+import java.util.concurrent.*;
+import java.util.regex.*;
+
+public class Solution {
+
+    static int maxSubsetSum(int[] arr) {
+
+        // O(n) Time, O(1) Space. Keep track of current max, notice that we could add first item or not.
+        
+        if (arr.length == 0) return 0;
+        if (arr.length == 1) return Math.max(0, arr[0]);
+
+        arr[0] = Math.max(0, arr[0]);
+        arr[1] = Math.max(arr[0], arr[1]);
+
+        for (int i = 2; i < arr.length; i++) {
+
+            arr[i] = Math.max(arr[i-1], arr[i] + arr[i-2]);
+        
+        }
+
+        return arr[arr.length - 1];
+    }
+
+    private static final Scanner scanner = new Scanner(System.in);
+
+    public static void main(String[] args) throws IOException {
+        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));
+
+        int n = scanner.nextInt();
+        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
+
+        int[] arr = new int[n];
+
+        String[] arrItems = scanner.nextLine().split(" ");
+        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
+
+        for (int i = 0; i < n; i++) {
+            int arrItem = Integer.parseInt(arrItems[i]);
+            arr[i] = arrItem;
+        }
+
+        int res = maxSubsetSum(arr);
+
+        bufferedWriter.write(String.valueOf(res));
+        bufferedWriter.newLine();
+
+        bufferedWriter.close();
+
+        scanner.close();
+    }
+}