#include <stdio.h>#include <stdlib.h>// Structure to represent a day in the calendar
struct Day {
char * dayName; // Dynamically allocated string for the day name
int date;
char * activity; // Dynamically allocated string for the activity description
};// Function to create a day
void create(struct Day * day) {
// Allocate memory for the day name and activity
day -> dayName = (char * ) malloc(sizeof(char) * 20); // Assuming day names are less than 20 characters
day -> activity = (char * ) malloc(sizeof(char) * 100); // Assuming activity descriptions are less than 100 characters// Input the day details
printf("Enter the day name:");
scanf("%s", day -> dayName);printf("Enter the date:");
scanf("%d", & day -> date);printf("Enter the activity for the day:");
scanf(" %[^\n]s", day -> activity); // Read the entire line, including spaces
}// Function to read data from the keyboard and create the calendar
void read(struct Day * calendar, int size) {
for (int i = 0; i < size; i++) {
printf("Enter details for Day %d:\n", i + 1);
create( & calendar[i]);
}
}// Function to display the calendar
void display(struct Day * calendar, int size) {
printf("\nWeek's Activity Details:\n");
for (int i = 0; i < size; i++) {
printf("Day %d:\n", i + 1);
printf("Day Name: %s\n", calendar[i].dayName);
printf("Date: %d\n", calendar[i].date);
printf("Activity: %s\n", calendar[i].activity);
printf("\n");
}
}// Function to free the dynamically allocated memory
void freeMemory(struct Day * calendar, int size) {
for (int i = 0; i < size; i++) {
free(calendar[i].dayName);
free(calendar[i].activity);
}
}int main() {
int size;
printf("Enter the number of days in the week:");
scanf("%d", & size);// Dynamically allocate memory for the calendar
struct Day * calendar = (struct Day * ) malloc(sizeof(struct Day) * size);// Check if memory allocation is successful
if (calendar == NULL) {
printf("Memory allocation failed. Exiting program.\n");
return 1;
}// Read and display the calendar
read(calendar, size);
display(calendar, size);// Free the dynamically allocated memory
freeMemory(calendar, size);// Free the memory allocated for the calendar array
free(calendar);return 0;
}

C Language online compiler

Write, Run & Share C Language code online using OneCompiler's C online compiler for free. It's one of the robust, feature-rich online compilers for C language, running the latest C version which is C18. Getting started with the OneCompiler's C editor is really simple and pretty fast. The editor shows sample boilerplate code when you choose language as 'C' and start coding!

Read inputs from stdin

OneCompiler's C online editor supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample C program which takes name as input and print your name with hello.

#include <stdio.h>
int main()
{
    char name[50];
    printf("Enter name:");
    scanf("%s", name);
    printf("Hello %s \n" , name );
    return 0;
    
}

About C

C language is one of the most popular general-purpose programming language developed by Dennis Ritchie at Bell laboratories for UNIX operating system. The initial release of C Language was in the year 1972. Most of the desktop operating systems are written in C Language.

Key features:

  • Structured Programming
  • Popular system programming language
  • UNIX, MySQL and Oracle are completely written in C.
  • Supports variety of platforms
  • Efficient and also handle low-level activities.
  • As fast as assembly language and hence used as system development language.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition if-else is used.

if(conditional-expression) {
   // code
} else {
   // code
}

You can also use if-else for nested Ifs and if-else-if ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to if-else-if ladder.

switch(conditional-expression) {    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
...    
    
default:     
 // code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  // code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while(condition) {  
 // code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {
  // code 
} while (condition);

Arrays

Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.

Syntax

One dimentional Array:

data-type array-name[size];

Two dimensional array:

data-type array-name[size][size];

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity.

Two types of functions are present in C

  1. Library Functions:

Library functions are the in-built functions which are declared in header files like printf(),scanf(),puts(),gets() etc.,

  1. User defined functions:

User defined functions are the ones which are written by the programmer based on the requirement.

How to declare a Function

return_type function_name(parameters);

How to call a Function

function_name (parameters)

How to define a Function

return_type function_name(parameters) {  
  //code
}