Print all subarrays of a given array

Problem: Given an array write an algorithm to print all the possible sub-arrays.

Example:

int [] a = {1, 2, 3};

Output: Possible subarrays –
{1}, {2}, {3}, {1, 2} , {2, 3}, {1, 2, 3}

Approach:

Click here to read about the recursive solution – Print all subarrays using recursion

Use three nested loops.
Outer loops will decide the starting point of a sub-array, call it as startPoint.
First inner loops will decide the group size (sub-array size). Group size starting from 1 and goes up array size. Let’s call is as grps.
The most inner loop will actually print the sub-array by iterating the given array from startPoint and print the next grps elements.
See the code below for more understanding.

Complete Code:

	public class PrintAllSubArrays {

	public void printSubArrays(int [] arrA){

	int arrSize = arrA.length;
	//start point
	for (int startPoint = 0; startPoint <arrSize ; startPoint++) {
	//group sizes
	for (int grps = startPoint; grps <=arrSize ; grps++) {
	//if start point = 1 then
	//grp size = 1 , print 1
	//grp size = 2, print 1 2
	//grp size = 3, print 1 2 3 ans so on
	for (int j = startPoint ; j < grps ; j++) {
	System.out.print(arrA[j] + " ");
	}
	System.out.println();
	}
	}
	}

	public static void main(String[] args) {
	int [] arrA = {1,2,3, 4};
	new PrintAllSubArrays().printSubArrays(arrA);
	}

	}

Output: