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Java Array Exercises: 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 contiguous subarray within a given array of integers which has 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 java.util.Arrays;
class solution	
{
	public static int largest_sum(int[] A)
	{
		int max_ele_val = 0;
		int max_end = 0;
		for (int i: A)
		{
			max_end = max_end + i;
			max_end = Integer.max(max_end, 0);

			max_ele_val = Integer.max(max_ele_val, max_end);
		}
		return max_ele_val;
	}
	public static void main(String[] args)
	{
		int[] A = {1, 2, -3, -4, 0, 6, 7, 8, 9};
		System.out.println("\nOriginal array: "+Arrays.toString(A));
		System.out.println("The largest sum of 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:

Flowchart: Find contiguous subarray within a given array of integers which has the largest sum.

Java Code Editor:

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Previous: Write a Java program to find maximum difference between two elements in a given array of integers such that smaller element appears before larger element.
Next: Write a Java program to find subarray which has the largest sum in a given circular array of integers.

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Java: Tips of the Day

Different between parseInt() and valueOf() in java?

Well, the API for Integer.valueOf(String) does indeed say that the String is interpreted exactly as if it were given to Integer.parseInt(String). However, valueOf(String) returns a new Integer() object whereas parseInt(String) returns a primitive int.

If you want to enjoy the potential caching benefits of Integer.valueOf(int), you could also use this eyesore:

Integer k = Integer.valueOf(Integer.parseInt("123"))

Now, if what you want is the object and not the primitive, then using valueOf(String) may be more attractive than making a new object out of parseInt(String) because the former is consistently present across Integer, Long, Double, etc.

Ref: https://bit.ly/3vRuIPY