Prime Number Program In C

Program to find whether a given number is Prime or Not

#include<stdio.h>

int main()
{
 /* Declaring variable for n=number, c=counter variable:holds 
 number of factor of 'n' */
 int n,c=0, i;
 
 // Inputting number
 printf("Enter number to check whether Prime or Not:");
 scanf("%d",&n);

 // Checking whether number valid or not
 if(n>0)
 {
  
 // Checking whether number is prime or not 
 for(i=1;i<=n;i++)
 {
  if(n%i==0)
    c=c+1;
 }
 
 if(c==2)
   printf("Prime Number");
 else
   printf("Not a Prime Number");
 }
 
 else 
   printf("Not a valid Number");

 return 0;
}

Program to print ( list ) all the prime number between 1 to n

#include<stdio.h>

int main()
{
 /* Declaring variable for n=number, c=counter variable:holds 
 number of factor of 'n' */
 int n,c, i,j;
 
 // Inputting number
 printf("Enter number till which you want to list prime number:");
 scanf("%d",&n);

 // Checking whether number valid or not
 
 if(n>0)
 {
  printf("List of Prime Numbers:");
 // Checking whether number is prime or not 
 for(i=1;i<=n;i++)
 {
  c=0;
  for(j=1;j<=i;j++)
  {
    if(i%j==0)
      c=c+1;
  }
 if(c==2)
   printf("%d ",i);
 }
 
 }
 else 
   printf("Not a valid Number");

 return 0;
}

Palindrome Program In C

Palindrome Program

C Program to determine Palindrome number

C Program to print (list) Palindrome number from 10 to n

C Program to find whether a number is Palindrome or not using recursion

C Program to enter a word and check whether it is palindrome or not using string function

C Program to enter a word and check whether it is palindrome or not without using string function

C PROGRAM TO DETERMINE PALINDROME NUMBER

Back To Palindrome Program

#include<stdio.h>
int main()
{
  // variable for a=number, n=to copy number, d=digit, rev=reverse of number
  int a,n,d=0,rev=0;

  // Inputting number
  printf("Enter any number to determine whether it is Palindrome or not:");
  scanf("%d",&a);

  // copying number in n
  n=a;

  // Determining whether number is palindrome or not
  while(n!=0)
  {
    d=n%10;
    rev=rev*10+d;
    n=n/10;
  }
           
  // Displaying Whether number is palindrome or not
  if(a==rev)
    printf("Palindrome number");
  else
    printf("Not a Palindrome Number");

  return 0;
}

C PROGRAM TO PRINT(LIST) PALINDROME NUMBER FROM 10 TO n

Back To Palindrome Program

#include<stdio.h>

int main()
{
  /*declaring variable for num=user wish, i=acts as number, n=to copy number, 
  d=digit, rev=reverse of number */
  int num,n,d=0,rev,i;

  // Inputting number
  printf("Enter number till which you want to list Palindrome Number:");
  scanf("%d",&num);

  printf("List of Palindrome Number:");
  for(i=10;i<=num;i++)
  {
    // copying number in n
    n=i;
    rev=0;
    // Determining whether number is palindrome or not
    while(n!=0)
    {
       d=n%10;
       rev=rev*10+d;
       n=n/10

    }
           
    // Displaying Whether number is palindrome or not
    if(i==rev)
    printf("%d ",i);
  }

  return 0;

}

C PROGRAM TO FIND WHETHER A NUMBER IS PALINDROME OR NOT USING RECURSION

Back To Palindrome Program

#include<stdio.h>

// Declaring global variable r=reverse, d=digit
int r=0, d=0;

// Defining function with parameter n = number
int rev(int n)
{
/* Base condition : Any condition where a recursive function 
or method does not invoke itself. */
if(n==0)
return r;

// Continue calling function rev or function invoke itself
else
{
 // Extracting digit
 d=n%10;
 
 // Finding reverse
 r=(r*10+d);
 
 // function invoke itself
 rev(n/10);
}
}

int main()
{
// Declaring variable n = number
int n;

// Declaring variable "r" to hold the reverse number
int r;

// Inputting Number
printf("Enter the Number : ");
scanf("%d",&n);

// Calling function "rev" with actual parameter "n" passed to it
r=rev(n);

// Checking and Displaying if a Number is palindrome or Not
if(r==n)
printf("%d is a Palindrome Number ",n);

else
 printf("%d is not a Palindrome Number ",n);

return 0;
}

C PROGRAM TO ENTER A WORD AND CHECK WHETHER IT IS PALINDROME OR NOT USING STRING FUNCTION

Back To Palindrome Program

// palindrom - When word = reverse of word then it is called palindrome
// Example : madam - palindrome, Madam - not palindrome, MadaM - palindrome

#include<stdio.h>
#include<string.h>

int main()
{
 // Declaring variable str=string 
 char word[50], word1[50];
 
 // Inputing string
 printf("Enter any word : ");
 scanf("%s",&word);

 // Copying word to word1
 strcpy(word1,word);
 
 // checking if palindrome or not
 if(strcmp(word,strrev(word1))==0)
 {
  printf("Entered word is a palindrome ");
 }
 
 else
  printf("Entered word is not palindrome ");

 return 0;
}

PALINDROME PROGRAM IN C WITHOUT USING STRING FUNCTION

Back To Palindrome Program

#include<stdio.h>

int main()
{
 // Declaring variable str=string 
 char word[50], revword[50];
 
 /* Declaring variable i=to iterate loop, l=length, 
 c=count the number of matched character */
 int i, j, l=0, c;
 
 // Inputing string
 printf("Enter any word : ");
 scanf("%s",&word);

 // finding length
 while(word[l]!='\0')
 l++;
 
 // Reversing string
 j=0;
 for(i=l-1;i>=0;i--)
 {
  revword[j]=word[i];
  j++;
 }
 revword[j]='\0';
 
 //checking if palindrome or not
 c=0;
 for(i=0;word[i]!='\0';i++)
 {
  if(revword[i]==word[i])
  c++;
 }
 
 if(c==l)
 {
  printf("Word is a palindrome ");
 }
 
 else
  printf("Word is not palindrome ");
 
 return 0;
}

Leap Year Program In C

Leap Year Program In C using if-else

// Leap year program in c using if-else

#include<stdio.h>

int main()
{
 // Declaring variable for y=year
 int y;
 
 // Inputing year
 printf("Enter year to check leap year or not: ");
 scanf("%d",&y);
 
 // Determining and displaying whether leap year or not
 if(y%4==0)
 {
  if(y%100==0 && y%400!=0)
  printf("Century year, But not a leap year");
  else
  printf("Leap year");
 }
 else
 printf("Not a Leap Year");

 return 0;
}

Leap Year Program In C Using Ternary

// Leap year program in c using ternary

#include<stdio.h>

int main()
{
 // Declaring variable "y" to input year and "leap" to determine leap year
 int y,leap;
 
 // Inputting year
 printf("Enter any year : ");
 scanf("%d",&y);
 
 // Checking if leaf year or not
 leap=(y%400==0)?:(y%100!=0)?(y%4==0)?1:0:0;

 if(leap==1)
 printf("The given year is leap year");
 else
 printf("The given year is not leap year");

 return 0;
}

C PROGRAM TO FIND FIBONACCI SERIES

WHAT IS FIBONACCI SERIES

Fibonacci series : Fibonacci series is one in which the nth term is sum of (n-1)th term and (n-2)th term. The first two numbers of series are 0 and 1.
For example: 0 1 1 2 3 5 8 13 21 and so on

Now we can write a c program to find fibonacci series in the following ways :

• C Program to find fibonacci series using loops
• C Program to find fibonacci series using function
• C Program to find fibonacci series using recursion

C PROGRAM TO FIND FIBONACCI SERIES USING LOOPS

//C PROGRAM TO PRINT FIBONACCI SERIES USING LOOPS

 
 #include<stdio.h>
 
 int main()
 {
  /* Declaring variable for n=number, f=first, s=second, 
  t=third number, i=to iterate the loop */
  int n,f,s,t,i;
  
  // Inputing number till where fibonacci series is to be printed
  printf("Enter the number till which you want to print fibonacci series:");
  scanf("%d",&n);
  
  // Determining and printing fibonacii series
  printf("Fibonacci Series: ");
  
  f=0;
  s=1;
  printf("%d %d ",f,s);
  for(i=3;i<=n;i++)
  {
   t=f+s;
   printf("%d ",t);
   f=s;
   s=t;
  }
  
  return 0;
 }

C PROGRAM TO FIND FIBONACCI SERIES USING FUNCTION

//C PROGRAM TO FIND FIBONACCI SERIES USING FUNCTION

#include<stdio.h>

void fibonacci(int n);
int main()
{

  int n;

  // Inputing number till where fibonacci series is to be printed
  printf("Enter the number till which you want to print fibonacci series:");
  scanf("%d",&n);
  
  fibonacci(n);
  return 0;
}

void fibonacci(int n)
{
  /* Declaring variable for f=first, s=second, 
  t=third number, i=to iterate the loop */
  int f,s,t,i;
  
  // Determining and printing fibonacii series
  printf("Fibonacci Series: ");
  
  f=0;
  s=1;
  printf("%d %d ",f,s);
  for(i=3;i<=n;i++)
  {
   t=f+s;
   printf("%d ",t);
   f=s;
   s=t;
  }
}

C PROGRAM TO FIND FIBONACCI SERIES USING RECURSION

//WRITE A C PROGRAM TO FIND FIBONACCI SERIES USING RECURSION
#include<stdio.h>

int fibonacci(int n);

  /* Declaring variable for f=first, s=second, 
  t=third number, i=to iterate the loop */
  int f,s,t,i;
  f=0;
  s=1;

int main()
{
   int n;
  // Inputing number till where fibonacci series is to be printed
  printf("Enter the number till which you want to print fibonacci series:");
  scanf("%d",&n);
  
  printf("Fibonacci Series: ");
  printf("%d %d ",f,s);
  
  fibonacci(n);
  return 0;
}

int fibonacci(int n)
{
 if(n==2)
 {
    return 0;
 }
 
 else
 {
    t=f+s;
    printf("%d ",t);
    f=s;
    s=t;
    fibonacci(n-1);
 }
}

Note : You can write much better code than these. So view these example and try to program by yourself. Use your own logic. This would improve your programming skills.

List Of C Programs

Here I am providing with random list of c programs. For complete list of c programs you can visit : C PROGRAMS

• C Program to reverse a string using strerev and without using strrev, using pointers and recursion
• C Program to find fibonacci series using loops, function and recursion
• C Program to add, subtract, multiply and divide two numbers
• Leap Year Program In C using if-else and ternary
• Pattern Programs In C

Reverse String In C / Reversing String In C

Reversing string in C / Reverse String In C seems to be a daunting task for the newbies but after reading this post you can easily reverse string in C.

What Is Reverse String In C

Reverse string in c is basically taking input( i.e sentence ) from console and then display the sentence from last character to first character.

The following Program to reverse string in c accepts a string from the user and print the reverse string. For example consider the following input from the user :

Input String : The site name is comp-psyche.com

Output String : moc.ehcysp-pmoc si eman etis ehT

There are various ways to reverse string in c. You can either use string function to reverse string in c or you can reverse string in c without using c string function.

• Reverse string in C using function ( c strrev() )
• Reverse String in C without using string function
• Reverse String in C using Recursion
• Reverse String in C using Pointer

REVERSE STRING IN C USING STRING FUNCTION ( c strrev() )

In the following program we will reverse string in c using string function streev()

#include<stdio.h>
#include<string.h>

int main()
{
 // Declaring variable str=string 
 char str[50];
 
 // Inputing string
 printf("Enter any string : ");
 gets(str);

 // Printing string and reversed string
 printf("String : %s\n",str);
 printf("Reversed string : %s",strrev(str));

 return 0;
}

REVERSE STRING IN C WITHOUT USING STRING FUNCTION

In the following program we will reverse string in c without using string function

int main()
{
 // Declaring variable str=string, revstr[50]=reverse string
 char str[50], revstr[50];
 
 // Declaring variable i=to iterate loop, l=length
 int i, j,l=0;
 
 // Inputing string
 printf("Enter any string : ");
 gets(str);

 // finding length
 while(str[l]!='\0')
 l++;
 
 // Reversing string
 j=0;
 for(i=l-1;i>=0;i--)
 {
  revstr[j]=str[i];
  j++;
 }
 revstr[j]='\0';
 
 // Printing string and reversed string
 printf("String : %s\n",str);
 printf("Reversed string : %s",revstr);

}

REVERSE STRING IN C USING RECURSION

In the following program we will reverse string in c using recursion

// Write a c program to reverse a string using recursion
#include<stdio.h>
void reverse (int index, char *str );

int main (void)

{

   char str[100];
   printf ("Enter any string : "); 
   gets(str);
 reverse (strlen(str) , str );
 return 0;

}

void reverse (int index, char *str )

{

  if (--index < 0 )

  {
       return ;
  }

  else
  {
        putchar ( *(str + index) ) ;  
        reverse (index, str) ;
  }

}

REVERSE STRING IN C USING POINTER

In the following program we will reverse string in c using pointer

// Write a C program to reverse a string using pointer
#include<stdio.h>
int main()
{
    
    // Declaring variable str = string and revstr = to store the revere string
    char str[50];
    char revstr[50];
    
    char *strptr = str; // strptr - holds the first position address of str
    char *revptr = revstr; // revptr - holds the first position address of revstr
    int i=-1;

    // Inputting string
    printf("Enter any string : ");
    gets(str);
   
    // strptr is pointed to the last position address
    while(*strptr)
    {
        strptr++;
        i++;
    }

    // string stored in str is copied to revstr
    while(i>=0)
{
       strptr--;
       *revptr = *strptr;
       revptr++;
       --i;
    }

    *revptr='\0';
  
    printf("Reverse of string is : %s",revstr);
  
    return 0;
}