Merge pull request #1196 from 007aneesh/main

kadane_algo_java

Author: akgmage

Diff for: Famous Algorithms/kadanes_algo.java

@@ -0,0 +1,80 @@
+/* Name : Aneesh
+Github username : 007aneesh
+Repository name : data-structures-and-algorithms
+Problem : Kadane's algorithm in Java
+Issue Number : #1180
+Problem statement : Given an integer array nums, find the subarray with the largest sum, and return its sum.
+
+Sample testcases: 
+
+Testcase 1 --> 
+
+Input: number of elements in array = 9
+nums = [-2,1,-3,4,-1,2,1,-5,4]
+Output: 6
+
+Testcase 2 -->
+Input: number of elements in array
+nums = [5,4,-1,7,8]
+Output: 23
+
+Time Complexity = O(n)
+Space Complexity = O(1)
+
+
+Explanation:
+This code asks the user to enter the number of elements in an array,
+and then prompts them to enter each element of the array one at a time.
+Once the array is complete, the code applies the Kadane's algorithm to
+find the maximum sum of any subarray within the array, and then prints 
+the result to the console.
+
+Kadane's algorithm is a way of finding the maximum sum of a contiguous subarray within an array,
+and it does so by keeping track of the maximum sum seen so far as it iterates through the array.
+At each step, it adds the current element to a running sum, and if that sum becomes negative,
+it resets the running sum to zero. If the running sum is ever greater than the maximum seen so far,
+it updates the maximum. Finally, it returns the maximum sum.
+*/
+
+// ----------------------------------------------------------------------------- code begins now!
+import java.util.Scanner;
+
+public class kadanes_algo {
+	public static int maxSubArraySum(int[] arr) {
+        if (arr == null || arr.length == 0) {
+            return 0;
+        }
+
+        int max = 0;
+        int sum = Integer.MIN_VALUE;
+
+        for (int i = 0; i < arr.length; i++) {
+            max += arr[i];
+
+            if (max < arr[i]) {
+                max = arr[i];
+            }
+
+            if (sum < max) {
+                sum = max;
+            }
+        }
+
+        return sum;
+    }
+
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        System.out.print("Enter the number of elements in the array: ");
+        int n = sc.nextInt();
+        int[] arr = new int[n];
+        System.out.println("Enter the elements of the array:");
+        for (int i = 0; i < n; i++) {
+            arr[i] = sc.nextInt();
+        }
+
+        int maxSum = maxSubArraySum(arr);
+        System.out.println("The maximum subarray sum is " + maxSum);
+    }
+
+}