Ruby program to sort an array in ascending order using quick sort

Program/Source Code:

The source code to sort an array in ascending order using quicksort is given below. The given program is compiled and executed successfully.

# Ruby program to sort an array in ascending order 
# using Quick Sort

def QuickSort(arr, first, last)
    pivot= 0;
    temp = 0;
    i    = 0;
    j    = 0;
        
    if(first < last)
            pivot = first;
            i = first;
            j = last;
            
            while(i<j)
                while(arr[i]<=arr[pivot] && i<last)
                    i=i + 1;
                end
                while (arr[j] > arr[pivot])
                    j = j - 1;
                end
                if(i < j)
                    temp   = arr[i];
                    arr[i] = arr[j];
                    arr[j] = temp;
                end
            end
            temp = arr[pivot];
            arr[pivot] = arr[j];
            arr[j] = temp;
            QuickSort(arr, first, j - 1);
            QuickSort(arr, j + 1, last);
    end
end

arr = [12,39,49,87,68];

QuickSort(arr,0,4);

i=0;
print "Sorted Array: \n";
while(i<5)
    print arr[i]," ";
    i=i+1;
end

Output:

Sorted Array: 
12 39 49 68 87 

Explanation:

In the above program, we defined a method QuickSort() to sort an array in ascending order. And, we use recursion to use apply the quick sort process effectively. Using the QuickSort() method, we divide the given array into small sub-arrays. Then we sort sub-arrays recursively.