From 0ae3ada50dd17677b7b505a5a059b70459b107ab Mon Sep 17 00:00:00 2001
From: Vishal Sharma <42766370+VishalSharma2000@users.noreply.github.com>
Date: Sun, 13 Oct 2019 19:46:27 +0530
Subject: [PATCH] Sorted Linked List

It will insert, delete and show the elements of the list. If the user either insert new element or delete any existing element in the list , the elements of the list will always be in the sorted form.
---
 List/sortedLinkedList.c | 164 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 164 insertions(+)
 create mode 100644 List/sortedLinkedList.c

diff --git a/List/sortedLinkedList.c b/List/sortedLinkedList.c
new file mode 100644
index 0000000..f9f2e4f
--- /dev/null
+++ b/List/sortedLinkedList.c
@@ -0,0 +1,164 @@
+#include<stdio.h>
+#include<stdlib.h>
+#include<conio.h>
+
+//defining global structure for the node
+typedef struct number{
+    int no;
+    struct number *next;
+}Num;
+
+//start struct pointer. This pointer will always point to the first node in the list
+Num *start = NULL;
+
+//Functoin declaration
+Num* createNode();
+void insert(int);
+void insertAtBeg(Num*);
+void insertAtEnd(Num*,Num*);
+void deleteNode(int);
+int view();
+
+//function defination
+Num* createNode(){
+    Num *temp;
+    temp = (Num*)malloc(sizeof(Num));
+    temp->next = NULL;
+    return (temp);
+}
+
+void insert(int num){
+    int status = 0;
+    
+    /*creating new node using createNode() and assigning value to it*/    
+    Num *newNode;
+    newNode = createNode();
+    newNode->no = num;
+    
+    if(start == NULL)                       //if the list is empty
+        start = newNode;
+    else{
+        if(start->no > num)                  
+            insertAtBeg(newNode);
+        /*if the first node of the list has the number greater than the current number than
+        the newNode will become the first node of the list*/
+        else{       
+        //traversing through the node for finding the number less than the current number.
+            Num *tempNode,*destNode = NULL;
+            /*destNode is the node which the number just smaller than the current number
+              tempNode is the node which has the number just bigger than the current number*/
+            tempNode = start;
+            
+            while(tempNode->no < num){
+                
+                if(tempNode->next == NULL){   //if the pointer has reached the last node
+                    status = 1;
+                    break;
+                }
+            
+            destNode = tempNode;              
+            tempNode = tempNode->next;
+            }
+                               
+        //if the point of insertion is in between
+        if(status == 0){
+            destNode->next = newNode;
+            newNode->next = tempNode;
+        }
+        //if the point of the insertion is at the end of the node
+        else if(status == 1){
+            insertAtEnd(newNode,tempNode);
+        }
+        
+        }
+    }
+}
+
+void insertAtBeg(Num *newNode){
+    newNode->next = start;
+    start = newNode;
+}
+
+void insertAtEnd(Num *newNode,Num *lastNode){
+    lastNode->next = newNode;
+}
+
+void deleteNode(int num){
+    Num *destNode,*tempNode;
+    destNode = start;
+    if(start->no == num){               //if the first node has the req number
+        start = start->next;
+    }else{
+        //tarvesing to the node which is having the required number
+        while(destNode->no != num){
+            tempNode = destNode;
+            destNode = destNode->next;
+        }
+    
+        tempNode->next = destNode->next;
+    }
+    //removing the allocated memory by malloc
+    free(destNode);
+}
+
+int view(){
+    if(start == NULL){
+        printf("List is empty");
+        return (NULL);   
+    }
+    else{
+        Num *tempNode;
+        tempNode = start;
+        printf("\nElements of List: ");
+        while(tempNode != NULL){
+            printf("%d ",tempNode->no);
+            tempNode = tempNode->next;
+        }
+        return (1);       
+    }
+    
+}
+
+//main function
+int main(){
+    int choice = 0 , no;
+    
+    while(1){
+        system("cls");
+        printf("1) Insert\n");
+        printf("2) Delete\n");
+        printf("3) View\n");
+        printf("4) Exit\n");
+        printf("Enter your choice: ");
+        scanf("%d",&choice);  
+        
+        switch(choice){
+            case 1:
+                printf("Enter number: ");
+                scanf("%d",&no);
+                insert(no);
+                view();
+                break;
+            case 2:
+                no = view();
+                if(no != NULL){
+                    printf("\nEnter number you want to remove: ");
+                    scanf("%d",&no);
+                    deleteNode(no);
+                    view();    
+                }
+                break;
+            case 3:
+                view();
+                break;
+            case 4:
+                exit(0);
+                break;
+            default:
+                printf("Invalid Input");
+        }
+        getch();  
+    }
+    
+    return (0);
+}