﻿ Java - Subarray within an array which has the largest sum

# Java: Find contiguous subarray within a given array of integers which has the largest sum

## Java Array: Exercise-66 with Solution

Write a Java program to find a contiguous subarray within a given array of integers with the largest sum.

In computer science, the maximum sum subarray problem is the task of finding a contiguous subarray with the largest sum, within a given one-dimensional array A[1...n] of numbers. Formally, the task is to find indices and with, such that the sum is as large as possible.

Example:
Input :
int[] A = {1, 2, -3, -4, 0, 6, 7, 8, 9}
Output:
The largest sum of contiguous sub-array: 30

Sample Solution:

Java Code:

``````// Import the necessary Java class.
import java.util.Arrays;

// Define a class named 'solution'.
class solution {
// Method to find the largest sum of a contiguous sub-array.
public static int largest_sum(int[] A) {
// Initialize variables for maximum element value and maximum ending here.
int max_ele_val = 0;
int max_end = 0;

// Iterate through the elements in array 'A'.
for (int i : A) {
max_end = max_end + i;

// Ensure that 'max_end' doesn't go below zero.
max_end = Integer.max(max_end, 0);

// Update 'max_ele_val' with the maximum value.
max_ele_val = Integer.max(max_ele_val, max_end);
}
return max_ele_val;
}

// Main method to demonstrate finding the largest sum of a contiguous sub-array.
public static void main(String[] args) {
// Initialize an array.
int[] A = {1, 2, -3, -4, 0, 6, 7, 8, 9};
System.out.println("\nOriginal array: " + Arrays.toString(A));

// Call the 'largest_sum' method to find and print the largest sum.
System.out.println("The largest sum of a contiguous sub-array: " + largest_sum(A));
}
}
```
```

Sample Output:

```Original array: [1, 2, -3, -4, 0, 6, 7, 8, 9]
The largest sum of contiguous sub-array: 30
```

Flowchart: Java Code Editor:

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