C program to check whether input alphabet is a vowel or not

#include <stdio.h>
 
int main()
{
  char ch;
 
  printf("Enter a character\n");
  scanf("%c", &ch);
 
  if (ch == 'a' || ch == 'A' || ch == 'e' || ch == 'E' || ch == 'i' || ch == 'I' || ch =='o' || ch=='O' || ch == 'u' || ch == 'U')
    printf("%c is a vowel.\n", ch);
  else
    printf("%c is not a vowel.\n", ch);
 

C program to print date

#include <stdio.h>
#include <conio.h>
#include <dos.h>
 
int main()
{
   struct date d;
 
   getdate(&d);
 
   printf("Current system date is %d/%d/%d",d.da_day,d.da_mon,d.da_year);
   getch();
   return 0;

c program to get ip address

#include<stdlib.h>
 
int main()
{
   system("C:\\Windows\\System32\\ipconfig");
 
   return 0;
}

C program to generate random numbers

#include <stdio.h>
#include <stdlib.h>
 
int main() {
  int c, n;
 
  printf("Ten random numbers in [1,100]\n");
 
  for (c = 1; c <= 10; c++) {
    n = rand() % 100 + 1;
    printf("%d\n", n);
  }
 
  return 0;

C program to print diamond pattern

#include <stdio.h>
 
int main()
{
  int n, c, k, space = 1;
 
  printf("Enter number of rows\n");
  scanf("%d", &n);
 
  space = n - 1;
 
  for (k = 1; k <= n; k++)
  {
    for (c = 1; c <= space; c++)
      printf(" ");
 
    space--;
 
    for (c = 1; c <= 2*k-1; c++)
      printf("*");
 
    printf("\n");
  }
 

C program to find nCr using function

#include <stdio.h>
 
long factorial(int);
long find_ncr(int, int);
long find_npr(int, int);
 
int main()
{
   int n, r;
   long ncr, npr;
 
   printf("Enter the value of n and r\n");
   scanf("%d%d",&n,&r);
 
   ncr = find_ncr(n, r);
   npr = find_npr(n, r);
 
   printf("%dC%d = %ld\n", n, r, ncr);
   printf("%dP%d = %ld\n", n, r, npr);
 
   return 0;
}
 
long find_ncr(int n, int r) {
   long result;
 
   result = factorial(n)/(factorial(r)*factorial(n-r));
 
   return result;
}

C program to shutdown or turn off computer

#include <stdio.h>
#include <stdlib.h>
 
int main()
{
   char ch;
 
   printf("Do you want to shutdown your computer now (y/n)\n");
   scanf("%c", &ch);
 
   if (ch == 'y' || ch == 'Y')
      system("C:\\WINDOWS\\System32\\shutdown -s");
 
   return 0;