ECE B ROCKS

                      5.Armstrong number

/* Source Code to display Armstrong number between two intervals entered by user. */

#include <stdio.h>
 main()
{
  int n1, n2, i, temp, num, rem;
  printf("Enter two numbers(intervals): ");
  scanf("%d %d", &n1, &n2);
  printf("Armstrong numbers between %d an %d are: ", n1, n2);
  for(i=n1+1; i<n2; ++i)
  {
      temp=i;
      num=0;
      while(temp!=0)
      {
          rem=(temp%10);
          num+=rem*rem*rem;
          temp/=10;
      }
      if(i==num)
      {
          printf("%d ",i);
      }
  }
  
}

Output

Enter two numbers(intervals): 100
400
Armstrong numbers between 100 and 400 are: 153 370 371

                              4.Prime numbers.

/* C program to display all prime numbers between Two interval entered by user. */
#include <stdio.h>
 main()
{
  int n1, n2, i, j, flag;
  printf("Enter two numbers(intevals): ");
  scanf("%d %d", &n1, &n2);
  printf("Prime numbers between %d and %d are: ", n1, n2);
  for(i=n1+1; i<n2; ++i)
  {
      flag=0;
      for(j=2; j<=i/2; ++j)
      {
        if(i%j==0)
        {
          flag=1;
          break;
        }
      }
      if(flag==0)
        printf("%d ",i);
  }
  }

Output

Enter two numbers(intervals): 20
50
Prime numbers between 20 and 50 are: 23 29 31 37 41 43 47

                                                       3.fibonacci series:

/* Displaying Fibonacci series up to certain number entered by user. */

#include <stdio.h>
 main()
{
  int t1=0, t2=1, display=0, num;
  printf("Enter an integer: ");
  scanf("%d",&num);
  printf("Fibonacci Series: %d+%d+", t1, t2); /* Displaying first two terms */
  display=t1+t2;
  for(display=t1+t2;display<num; display=t1+t2;)  {
      printf("%d+",display);
      t1=t2;
      t2=display;
     
  }
  
}

Output

Enter an integer: 200
Fibonacci Series: 0+1+1+2+3+5+8+13+21+34+55+89+144+

                                                 1.Factorial of a number:


/* C program to display factorial of an integer if user enters 

non-negative integer. */ #include <stdio.h> main() { int n, count; float factorial=1; printf("Enter an integer: "); scanf("%d",&n); if ( n< 0) printf("Error!!! Factorial of negative number doesn't exist."); else { for(count=1;count<=n;count++) /* for loop terminates if count>n */ { factorial*=count; /* factorial=factorial*count */ } printf("Factorial = %f",factorial); } }

Output 1

Enter an integer: -5
Error!!! Factorial of negative number doesn't exist.

Output 2

Enter an integer: 10
Factorial = 3628800

  

      2.Fibonacci series

/* Displaying Fibonacci sequence up to nth term where n is    entered by user. */#include <stdio.h>
int main()
{
  int count, n, t1=0, t2=1, display=0;
  printf("Enter number of terms: ");
  scanf("%d",&n);
  printf("Fibonacci Series: %d+%d+", t1, t2); /* Displaying first two terms */
  count=2;    /* count=2 because first two terms are already  displayed. */  while (count<n)  
  {
      display=t1+t2;
      t1=t2;
      t2=display;
      ++count;
      printf("%d+",display);
  }
  return 0;
}

Output

Enter number of terms: 10
Fibonacci Series: 0+1+1+2+3+5+8+13+21+34+