c program to find the factorial of a number, c program, factorial

#include<stdio.h>
 
long factorial(int);
 
main()
{
   int number;
   long fact = 1;
 
   printf("Enter a number to calculate it's factorial\n");
   scanf("%d",&number);
 
   printf("%d! = %ld\n", number, factorial(number));
 
   return 0;
}
 
long factorial(int n)
{
   int c;
   long result = 1;
 
   for( c = 1 ; c <= n ; c++ )
         result = result*c;
 
   return ( result );
}

c program to generate Fibonacci series,for loop, Fibonacci series

#include<stdio.h>

main()
{
   int n, first = 0, second = 1, next, c;

   printf("Enter the number of terms\n");
   scanf("%d",&n);

   printf("First %d terms of Fibonacci series are :-\n",n);

   for ( c = 0 ; c < n ; c++ )
   {
      if ( c <= 1 )
         next = c;
      else
      {
         next = first + second;
         first = second;
         second = next;
      }
      printf("%d\n",next);
   }

   return 0;
}

c program to read a file, read a file, program

#include<stdio.h>
#include<stdlib.h>
 
main()
{
   char ch, file_name[25];
   FILE *fp;
 
   printf("Enter the name of file you wish to see ");
   gets(file_name);
 
   fp = fopen(file_name,"r"); // read mode
 
   if( fp == NULL )
   {
      perror("Error while opening the file.\n");
      exit(EXIT_FAILURE);
   }
 
   printf("The contents of %s file are :- \n\n", file_name);
 
   while( ( ch = fgetc(fp) ) != EOF )
      printf("%c",ch);
 
   fclose(fp);
   return 0;
}

c programm for palindrome number, check a number as palindrome number, to generate palindrome

#include <stdio.h>
 
main()
{
   int n, reverse = 0, temp;
 
   printf("Enter a number to check if it is a palindrome or not\n");
   scanf("%d",&n);
 
   temp = n;
 
   while( temp != 0 )
   {
      reverse = reverse * 10;
      reverse = reverse + temp%10;
      temp = temp/10;
   }
 
   if ( n == reverse )
      printf("%d is a palindrome number.\n", n);
   else
      printf("%d is not a palindrome number.\n", n);
 
   return 0;
}

c programm for prime number, check a number as prime number, to generate prime number

#include<stdio.h>
 
main()
{
   int n, c = 2;
 
   printf("Enter a number to check if it is prime\n");
   scanf("%d",&n);
 
   for ( c = 2 ; c <= n - 1 ; c++ )
   {
      if ( n%c == 0 )
      {
         printf("%d is not prime.\n", n);
  break;
      }
   }
   if ( c == n )
      printf("%d is prime.\n", n);
 
   return 0;
}