Dynamic Array in C - Hacker Rank Solution

 TASK : 

Snow Howler is the librarian at the central library of the city of HuskyLand. He must handle requests which come in the following forms:

1 x y : Insert a book with  pages at the end of the  shelf.

2 x y : Print the number of pages in the  book on the  shelf.

3 x : Print the number of books on the  shelf.

Input Format

The first line contains an integer , the number of shelves in the library.
The second line contains an integer , the number of requests.
Each of the following  lines contains a request in one of the three specified formats.

Output Format

Write the logic for the requests of type 1. The logic for requests of types 2 and 3 are provided.

Sample Input 0

5
5
1 0 15
1 0 20
1 2 78
2 2 0
3 0

Sample Output 0

78
2

Explanation 0

There are  shelves and  requests, or queries.
- 1 Place a  page book at the end of shelf .
- 2 Place a  page book at the end of shelf .
- 3 Place a  page book at the end of shelf .
- 4 The number of pages in the  book on the  shelf is 78.
- 5 The number of books on the  shelf is 2.

                               

             PROGRAM CODE

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

int* total_number_of_books;

/*
 * This stores the total number of pages in each book of each shelf.
 * The rows represent the shelves and the columns represent the books.
 */
int** total_number_of_pages;
int main()
{
    int total_number_of_shelves;
    scanf("%d", &total_number_of_shelves);

    total_number_of_books = calloc(total_number_of_shelves, sizeof(int));

    int total_number_of_queries;
    scanf("%d", &total_number_of_queries);

    total_number_of_pages = malloc(total_number_of_shelves * sizeof(int *));
    for (int i = 0; i < total_number_of_shelves; i++) 
    {
        total_number_of_pages[i] = calloc(1100, sizeof(int));
    }

    while (total_number_of_queries--) 
    {
        int type_of_query;
        scanf("%d", &type_of_query);

        if (type_of_query == 1) 
        {
            /*
             * Process the query of first type here.
             */
            int shelf, pages;
            scanf("%d %d", &shelf, &pages);
            total_number_of_books[shelf]++;
            int *book = total_number_of_pages[shelf];
            while (*book != 0)
                book++;
            *book = pages;
        } 
        else if (type_of_query == 2) 
        {
            int x, y;
            scanf("%d %d", &x, &y);
            printf("%d\n", *(*(total_number_of_pages + x) + y));
        } 
        else 
        {
            int x;
            scanf("%d", &x);
            printf("%d\n", *(total_number_of_books + x));
        }
    }

    if (total_number_of_books) 
    {
        free(total_number_of_books);
    }
    
    for (int i = 0; i < total_number_of_shelves; i++) 
    {
        if (*(total_number_of_pages + i)) 
        {
            free(*(total_number_of_pages + i));
        }
    }
    
    if (total_number_of_pages) 
    {
        free(total_number_of_pages);
    }
    
    return 0;
}

1."Hello World!" in C Hackerrank Solution

Task

This challenge requires you to print  on a single line, and then print the already provided input string to stdout . If you are not familiar with C, you may want to read about the printf() command.

Example

The required output is:

Hello, World! 

Life is beautiful  

                  Program Code

#include <stdio.h>

#include <string.h>

#include <math.h>

#include <stdlib.h>

int main() 

{

    

    char s[100];

    scanf("%[^\n]%*c", &s);

    printf("Hello, World!\n%s", s);    

    return 0;

}