}
Write a program to swap two numbers?
#include <stdio.h>
int main(){
float a, b, temp;
printf("Enter value of a: ");
scanf("%f",&a);
printf("Enter value of b: ");
scanf("%f",&b);
temp = a; /* Value of a is stored in variable temp */
a = b; /* Value of b is stored in variable a */
b = temp; /* Value of temp(which contains initial
value of a) is stored in variable b*/
printf("\nAfter swapping, value of a
= %.2f\n", a);
printf("After swapping, value of b =
%.2f", b);
return 0;
}
Write a program to Check Whether a Number is Even
or Odd?
#include <stdio.h>
int main(){
int num;
printf("Enter an integer you want to
check: ");
scanf("%d",&num);
if((num%2)==0) /* Checking whether remainder is 0 or
not. */
printf("%d is even.",num);
else
printf("%d is odd.",num);
return 0;
}
Write a program to Check Whether a Character is Vowel or consonant?
#include <stdio.h>
int main(){
char c;
printf("Enter an alphabet: ");
scanf("%c",&c);
if(c=='a'||c=='A'||c=='e'||c=='E'||c=='i'||c=='I'||c=='o'||c=='O'||c=='u'||c=='U')
printf("%c is a vowel.",c);
else
printf("%c is a consonant.",c);
return 0;
}
Check
Leap Year?
#include <stdio.h>
int main(){
int year;
printf("Enter a year: ");
scanf("%d",&year);
if(year%4 == 0)
{
if( year%100 == 0) /* Checking for a
century year */
{
if ( year%400 == 0)
printf("%d is a leap
year.", year);
else
printf("%d is not a leap
year.", year);
}
else
printf("%d is a leap
year.", year );
}
else
printf("%d is not a leap
year.", year);
return 0;
}
Calculate
Sum of Natural Numbers?
#include <stdio.h>
int main()
{
int n, count, sum=0;
printf("Enter an integer: ");
scanf("%d",&n);
count=1;
while(count<=n) /* while loop terminates if count>n
*/
{
sum+=count; /* sum=sum+count */
++count;
}
printf("Sum = %d",sum);
return 0;
}
Find the Largest Number Among
Three Numbers?
#include <stdio.h>
int main(){
float a, b, c;
printf("Enter three numbers: ");
scanf("%f %f %f", &a, &b,
&c);
if(a>=b && a>=c)
printf("Largest number =
%.2f", a);
if(b>=a && b>=c)
printf("Largest number =
%.2f", b);
if(c>=a
&& c>=b)
printf("Largest number =
%.2f", c);
return 0;
}
Check Character is an
alphabet or not?
#include <stdio.h>
int main()
{
char c;
printf("Enter a character: ");
scanf("%c",&c);
if( (c>='a'&& c<='z') || (c>='A'
&& c<='Z'))
printf("%c is an alphabet.",c);
else
printf("%c is not an
alphabet.",c);
return 0;
}
Check Whether a Number is
Positive or Negative or Zero.
#include <stdio.h>
int main()
{
float num;
printf("Enter a number: ");
scanf("%f",&num);
if (num<=0)
{
if (num==0)
printf("You entered zero.");
else
printf("%.2f is negative.",num);
}
else
printf("%.2f is positive.",num);
return 0;
}
Generate
Multiplication Table?
#include <stdio.h>
int main()
{
int n, i;
printf("Enter an integer to find
multiplication table: ");
scanf("%d",&n);
for(i=1;i<=10;++i)
{
printf("%d * %d = %d\n", n, i,
n*i);
}
return 0;
}
Reverse
an Integer?
#include <stdio.h>
int main()
{
int n, reverse=0, rem;
printf("Enter
an integer: ");
scanf("%d", &n);
while(n!=0)
{
rem=n%10;
reverse=reverse*10+rem;
n/=10;
}
printf("Reversed Number = %d",reverse);
return 0;
}
Check
Palindrome Number?
#include <stdio.h>
int main()
{
int n, reverse=0, rem,temp;
printf("Enter an integer: ");
scanf("%d", &n);
temp=n;
while(temp!=0)
{
rem=temp%10;
reverse=reverse*10+rem;
temp/=10;
}
/* Checking
if number entered by user and it's reverse number is equal. */
if(reverse==n)
printf("%d is a palindrome.",n);
else
printf("%d is not a
palindrome.",n);
return 0;
}
Check
Prime Number
#include <stdio.h>
int main()
{
int n, i, flag=0;
printf("Enter a positive integer: ");
scanf("%d",&n);
for(i=2;i<=n/2;++i)
{
if(n%i==0)
{
flag=1;
break;
}
}
if (flag==0)
printf("%d is a prime number.",n);
else
printf("%d is not a prime
number.",n);
return 0;
}
Write to a Sentence to a File?
#include <stdio.h>
#include <stdlib.h> /* For exit() function */
int main()
{
char c[1000];
FILE *fptr;
fptr=fopen("program.txt","w");
if(fptr==NULL){
printf("Error!");
exit(1);
}
printf("Enter a sentence:\n");
gets(c);
fprintf(fptr,"%s",c);
fclose(fptr);
return 0;
}
Read a String of Text from File
#include <stdio.h>
#include <stdlib.h>
/* For exit() function*/
int main()
{
char c[1000];
FILE *fptr;
if ((fptr=fopen("program.txt","r"))==NULL){
printf("Error! opening file");
exit(1); /* Program exits if file pointer
returns NULL. */
}
fscanf(fptr,"%[^\n]",c);
printf("Data from file:\n%s",c);
fclose(fptr);
return 0;
}
Fibonacci
series up to n terms?
#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;
}
Factorial program in c using recursion?
#include<stdio.h>
long factorial(int);
int main()
{
int n;
long f;
printf("Enter an integer to find factorial\n");
scanf("%d", &n);
if (n < 0)
printf("Negative integers are not allowed.\n");
else
{
f = factorial(n);
printf("%d! = %ld\n", n, f);
}
return 0;
}
long factorial(int n)
{
if (n == 0)
return 1;
else
return(n * factorial(n-1));
}
Factorial program in c using for loop
#include <stdio.h>
int main()
{
int c, n, fact = 1;
printf("Enter a number to calculate it's factorial\n");
scanf("%d", &n);
for (c = 1; c <= n; c++)
fact = fact * c;
printf("Factorial of %d = %d\n", n, fact);
return 0;
}
