Create Swapping_node.cpp

Linked List/Swapping_node.cpp

@@ -0,0 +1,72 @@
+#include <iostream>
+
+using namespace std;
+class Node {
+
+public:
+    int data;
+    class Node* next;
+    Node(int val, Node* next)
+        : data(val)
+        , next(next)
+    {
+    }
+    void printList()
+    {
+        Node* node = this;
+        while (node != NULL) {
+            cout << node->data << " ";
+            node = node->next;
+        }
+        cout << endl;
+    }
+};
+void push(Node** head_ref, int new_data)
+{
+    (*head_ref) = new Node(new_data, *head_ref);
+}
+
+void swap(Node*& a, Node*& b)
+{
+    Node* temp = a;
+    a = b;
+    b = temp;
+}
+
+void swapNodes(Node** head_ref, int x, int y)
+{
+    if (x == y)
+        return;
+
+    Node **a = NULL, **b = NULL;
+    while (*head_ref) {
+
+        if ((*head_ref)->data == x) {
+            a = head_ref;
+        }
+        else if ((*head_ref)->data == y) {
+            b = head_ref;
+        }
+        head_ref = &((*head_ref)->next);
+    }
+    if (a && b) {
+        swap(*a, *b);
+        swap(((*a)->next), ((*b)->next));
+    }
+}
+int main()
+{
+    Node* start = NULL;  
+    push(&start, 7);
+    push(&start, 6);
+    push(&start, 5);
+    push(&start, 4);
+    push(&start, 3);
+    push(&start, 2);
+    push(&start, 1); 
+    cout << "Linked list before calling swapNodes() ";
+    start->printList(); 
+    swapNodes(&start, 6, 1);  
+    cout << "Linked list after calling swapNodes() ";
+    start->printList();
+}