Solved Sorting Linked List in C++

[pulkitgarg04]

I have solved Sorting Linked List in C++ as per issue #280.

[AbhishekSAngadi]

#include
using namespace std;

// Node structure
struct Node {
int data;
Node* next;
Node(int x) : data(x), next(nullptr) {}
};

// Function to split the linked list into two halves
void splitList(Node* source, Node** frontRef, Node** backRef) {
Node* fast;
Node* slow;
slow = source;
fast = source->next;

// Move 'fast' two nodes and 'slow' one node
while (fast != nullptr) {
    fast = fast->next;
    if (fast != nullptr) {
        slow = slow->next;
        fast = fast->next;
    }
}

*frontRef = source;
*backRef = slow->next;
slow->next = nullptr;

}

// Function to merge two sorted lists
Node* sortedMerge(Node* a, Node* b) {
Node* result = nullptr;

// Base cases
if (a == nullptr)
    return b;
else if (b == nullptr)
    return a;

// Pick either a or b, and recur
if (a->data <= b->data) {
    result = a;
    result->next = sortedMerge(a->next, b);
} else {
    result = b;
    result->next = sortedMerge(a, b->next);
}
return result;

}

// Merge Sort function
void mergeSort(Node** headRef) {
Node* head = headRef;
Node a;
Node* b;

// Base case: length 0 or 1
if ((head == nullptr) || (head