Answer to Question #211874 in C for kaushal

Question

1) Write a Menu driven C program to implement the following operations

in the linked list.

 Insert after a given node. 

 Insert before a given node.

 Delete a given node.

Answer 1

#include <stdio.h> 
#include <stdlib.h>

// Here is your linked list node 
struct node { 
    int info; 
    struct node* link; 
}; 

struct node* start = NULL; 
int isCreated = 0;

// This is method for create the list
// Note: Without Creating list there will be no operation perform
void createList() 
{     
    // check list is created or not
    if(isCreated == 0 ){
        isCreated = 1;
        printf("\n List is Created. \n");
    }    
    else { 
        printf("\n List is Already Created. \n");
    } 
} 
  
// This is method for display the list that you created
void showList() 
{ 
    struct node* temp; 

    // check list is created or not
    if(isCreated == 0 ){
        printf("No List Create Yet, Please Create List First!");        
    }else{
        // check list is empty or not
        if (start == NULL) {
            printf("\nList is empty\n"); 
        }else { 
            // start display all info until temp not equal to Null
            temp = start; 
            printf("============== Your List Start ==================\n");
            while (temp != NULL) {                 
                printf("%d\t", temp->info); 
                temp = temp->link; 
            } 
            printf("\n============== Your List End ==================");
        } 
    }
} 
  
// This is method for insert the node at the starting point list
void insertStart() 
{ 
    // check list is created or not
    if(isCreated == 0 ){
        printf("No List Create Yet, Please Create List First!");        
    }else{
            int data; 
            struct node* temp; 

            // malloc method is use here for dynamic memory allocation to node
            temp = malloc(sizeof(struct node)); 
            printf("\nEnter number to"
                   " be inserted : "); 
            scanf("%d", &data); 
            // pointer go to the temp and assign to the start            
            temp->info = data;             
            temp->link = start; 
            start = temp; 
    }    
} 
  
// This is method for insert the node at the ending point list
void insertEnd() 
{ 
    // check list is created or not
    if(isCreated == 0 ){
        printf("No List Create Yet, Please Create List First!");
     
    }else{

        int data; 
        struct node *temp, *head; 
        // malloc method is use here for dynamic memory allocation to node
        temp = malloc(sizeof(struct node));       
        // Enter the number 
        printf("\nEnter number to"
               " be inserted : "); 
        scanf("%d", &data); 
      
        // Changes links 
        temp->link = 0; 
        temp->info = data; 
        head = start; 
        // Loop until not getting null value in link 
        while (head->link != NULL) { 
            head = head->link; 
        } 
        // Set Node At the Last
        head->link = temp;         
    }
} 
  
// This is method for insert the node at the given position
void insertPosition() 
{ 
    // check list is created or not
    if(isCreated == 0 ){
        printf("No List Create Yet, Please Create List First!");
    }else{

        struct node *temp, *newnode; 
        int pos, data, i = 1; 

        // malloc method is use here for dynamic memory allocation to node
        newnode = malloc(sizeof(struct node)); 
        
        printf("\nEnter position and data :"); 
        scanf("%d %d", &pos, &data); 
              
        temp = start; 
        newnode->info = data; 
        newnode->link = 0; 
        // Find the position
        while (i < pos - 1) { 
            temp = temp->link; 
            i++; 
        } 
        // Set the newnode
        newnode->link = temp->link; 
        temp->link = newnode; 
    }
} 
  
// This is method for delete the node at starting point of list
void deleteFirst() 
{ 
    // check list is created or not
    if(isCreated == 0 ){
        printf("No List Create Yet, Please Create List First!");
        
    }else{
        struct node* temp; 
        // check list is empty or not
        if (start == NULL) 
            printf("\nList is empty\n"); 
        else { 

            temp = start; 
            start = start->link; 
            // Remove First Node
            free(temp); 
        } 
    }
} 

// This is method for delete the node at ending point of list
void deleteEnd() 
{ 
    // check list is created or not
    if(isCreated == 0 ){
        printf("No List Create Yet, Please Create List First!");
        
    }else{

        struct node *temp, *prevnode; 
        // check list is empty or not
        if (start == NULL) 
            printf("\nList is Empty\n"); 
        else { 
            temp = start; 
            // loop till the end
            while (temp->link != 0) { 
                prevnode = temp; 
                temp = temp->link; 
            }           
            // Free the last node
            free(temp); 
            prevnode->link = 0; 
        }     
    }
} 
  
// This is method for delete the node at given index point
void deletePosition() 
{ 
    // check list is created or not
    if(isCreated == 0 ){
        printf("No List Create Yet, Please Create List First!");
    }else{
        struct node *temp, *position; 
        int i = 1, pos;           
        // check list is empty or not
        if (start == NULL) 
            printf("\nList is empty\n");       
        
        else {         
            printf("\nEnter position : ");               
            scanf("%d", &pos);             
            position = malloc(sizeof(struct node)); 
            temp = start;         
            //  Its check until getting position
            while (i < pos - 1) { 
                temp = temp->link; 
                i++; 
            }
            // This below code will basically change the links of node
            position = temp->link;                         
            temp->link = position->link;          
            // Free the position that user entered
            free(position); 
        }
    } 
} 

int main() 
{ 
    int choice; 
    while (1) {   
        printf("\n\t1  For create a list\n");         
        printf("\t2  For display a list\n");         
        printf("\t3  For insertion at begin\n"); 
        printf("\t4  For insertion at end\n"); 
        printf("\t5  For insertion at any position\n"); 
        printf("\t6  For deletion of begin\n"); 
        printf("\t7  For deletion of end\n"); 
        printf("\t8  For deletion of element at any position\n");                     
        printf("\t0  To exit\n"); 
        printf("\nEnter Choice :\n"); 
        scanf("%d", &choice);   
        switch (choice) { 
        case 1:         
            createList();
            break; 
        case 2: 
            showList();            
            break; 
        case 3: 
            insertStart();             
            break; 
        case 4: 
            insertEnd();             
            break; 
        case 5: 
            insertPosition();             
            break; 
        case 6: 
            deleteFirst();             
            break; 
        case 7: 
            deleteEnd();             
            break;         
        case 8: 
            deletePosition(); 
            break;       
        case 0: 
            exit(1); 
            break; 
        default: 
            printf("Please Enter Correct Choice!\n"); 
        } 
    } 
    return 0;
}