Added Singly Linked List in cpp

C Programming Language/Linked Lists/Singly Linked lists/singlylinkedlist.cpp

@@ -0,0 +1,335 @@
+//Program for singly linked list
+
+#include <iostream>
+using namespace std;
+#include <string.h>
+
+class node
+{
+friend class list;
+int rollno;
+char name[10];
+int year;
+node *next;
+
+public:
+node(int d,int r,char s[10])
+{
+	rollno=d;
+	year=r;
+	strcpy(name,s);
+	next=NULL;
+}
+
+};
+
+class list
+{
+	node *head;
+
+    public:
+	list()
+	{
+		head=NULL;
+	}
+	void createmember()
+	{
+		int r,y;
+		char a;
+		char nm[10];
+		node *temp,*ptr;
+
+        do
+        {
+
+            cout<<"Enter roll no, year and name: "<<endl;
+            cin>>r>>y>>nm;
+
+            temp= new node(r,y,nm);
+
+			if(head==NULL)
+			{
+				head=temp;
+				cout<<"Node is inserted"<<endl;
+			}
+			else
+			{
+				ptr=head;
+				while(ptr->next!=NULL)
+				{
+					ptr=ptr->next;
+				}
+				ptr->next=temp;
+				cout<<"Node is inserted"<<endl;
+			}
+            cout<<"\nDo you want to continue the process, if yes say 'y'";
+            cin>>a;
+        }while(a=='y'||a=='Y');
+
+	}
+
+	void display()
+	{
+		node *ptr;
+
+		if(head==NULL)
+		{
+			cout<<"List is empty"<<endl;
+		}
+		else
+		{
+			ptr=head;
+			while(ptr!=NULL)
+			{
+				cout<<"Rollno: "<<ptr->rollno<<endl;
+				cout<<"Year: "<<ptr->year<<endl;
+				cout<<"Name: "<<ptr->name<<endl;
+				cout<<endl;
+				ptr=ptr->next;
+			}
+		}
+	}
+	int count()
+	{
+		node *ptr;
+		int count=0;
+
+		if(head==NULL)
+		{
+			return 0;
+		}
+		else
+		{
+			ptr=head;
+			while(ptr!=NULL)
+			{
+				count++;
+				ptr=ptr->next;
+			}
+			return count;
+		}
+	}
+	void insert()
+	{
+			int r,y,i,pos;
+			char nm[10];
+			node *temp,*ptr;
+
+			cout<<"Enter roll no, year and name: "<<endl;
+			cin>>r>>y>>nm;
+			temp= new node(r,y,nm);
+
+			cout<<"Enter the position you want to insert: "<<endl;
+			cin>>pos;
+
+			if(pos==1)
+			{
+				temp->next=head;
+				head=temp;
+				cout<<"Node is inserted"<<endl;
+			}
+			else if(pos<=count()+1)
+			{
+				ptr=head;
+				for(i=2;i<=pos-1;i++)
+				{
+					ptr=ptr->next;
+				}
+				temp->next=ptr->next;
+				ptr->next=temp;
+                cout<<"Node is inserted"<<endl;
+			}
+            else
+                cout<<"Position not found!"<<endl;
+
+//			LAST NODE
+//          {
+//				ptr=head;
+//				while(ptr->next!=NULL)
+//					ptr=ptr->next;
+//				ptr->next=temp;
+//			}
+
+	}
+	void deletemember()
+	{
+		int data;
+		node *ptr,*prev;
+		int flag=0;
+        ptr=head;
+
+		if(head==NULL)
+        {
+            cout<<"List is empty!"<<endl;
+            return;
+        }
+
+		cout<<"Enter the rollno to be deleted"<<endl;
+		cin>>data;
+		if(ptr->rollno==data)
+        {
+            head=head->next;
+            delete ptr;
+            flag=1;
+        }
+        else
+        {
+            while((ptr!=NULL)&&(ptr->rollno!=data))
+            {
+                prev=ptr;
+                ptr=ptr->next;
+            }
+            if(ptr==NULL)
+                flag=0;
+            else
+            {
+                prev->next=ptr->next;
+                ptr->next=NULL;
+                delete ptr;
+                flag=1;
+            }
+        }
+        if(flag==0)
+            cout<<"Roll no. not present!"<<endl;
+        else
+            cout<<"Node successfully deleted!"<<endl;
+
+        display();
+
+	}
+
+};
+
+int main() {
+
+	list l1;
+	int ch;
+	int count=0;
+
+	l1.createmember();
+	cout<<"1.Display"<<endl;
+	cout<<"2.Count"<<endl;
+	cout<<"3.Insert"<<endl;
+	cout<<"4.Delete"<<endl;
+	cout<<"5.Exit"<<endl;
+
+	while(1)
+	{
+		cout<<"Enter your choice: "<<endl;
+		cin>>ch;
+		switch(ch)
+		{
+			case 1:
+					l1.display();
+					break;
+
+			case 2:
+                    cout<<"Total number of nodes: "<<l1.count()<<endl;
+					break;
+
+			case 3:
+					l1.insert();
+					break;
+
+			case 4:
+					l1.deletemember();
+					break;
+
+            case 5:
+                    cout<<"Program closed!"<<endl;
+                    //exit(1);
+                    break;
+
+			default:
+					cout<<"Invalid choice"<<endl;
+					break;
+
+		}
+	}
+	return 0;
+}
+
+/*
+OUTPUT:
+
+Enter roll no, year and name:
+1
+2000
+abc
+Node is inserted
+
+Do you want to continue the process, if yes say 'y' or say 'n' y
+Enter roll no, year and name:
+2
+2000
+abc
+Node is inserted
+
+Do you want to continue the process, if yes say 'y' or say 'n' n
+1.Display
+2.Count
+3.Insert
+4.Delete
+5.Exit
+Enter your choice:
+1
+Rollno: 1
+Year: 2000
+Name: abc
+
+Rollno: 2
+Year: 2000
+Name: abc
+
+Enter your choice:
+3
+Enter roll no, year and name:
+3
+2000
+abc
+Enter the position you want to insert:
+4
+Position not found!
+Enter your choice:
+4
+Enter the rollno to be deleted
+3
+Roll no. not present!
+Enter your choice:
+4
+Enter the rollno to be deleted
+1
+Node successfully deleted
+Enter your choice:
+1
+Rollno: 2
+Year: 2000
+Name: abc
+
+Enter your choice:
+2
+Total number of nodes: 1
+Enter your choice:
+3
+Enter roll no, year and name:
+1
+2000
+abc
+Enter the position you want to insert:
+1
+Node is inserted
+Enter your choice:
+1
+Rollno: 1
+Year: 2000
+Name: abc
+
+Rollno: 2
+Year: 2000
+Name: abc
+
+Enter your choice:
+5
+Program closed!
+
+*/