SIMPLE PROGRAMS EASY WAY TO LEARN
1.sum of two numbers
#include <stdio.h>
int main() {
int number1, number2, sum;
printf("Enter two integers: ");
scanf("%d %d", &number1, &number2);
// calculating sum
sum = number1 + number2;
printf("%d + %d = %d", number1, number2, sum);
return 0;
}2.multiplying two floating point numbers
#include <stdio.h>
int main() {
double a, b, product;
printf("Enter two numbers: ");
scanf("%lf %lf", &a, &b);
// Calculating product
product = a * b;
// Result up to 2 decimal point is displayed using %.2lf
printf("Product = %.2lf", product);
return 0;
}
Output
Enter two numbers: 2.4
1.12
Product = 2.69
3.C Program to Find GCD of two Numbers
#include <stdio.h>
int main()
{
int n1, n2, i, gcd;
printf("Enter two integers: ");
scanf("%d %d", &n1, &n2);
for(i=1; i <= n1 && i <= n2; ++i)
{
// Checks if i is factor of both integers
if(n1%i==0 && n2%i==0)
gcd = i;
}
printf("G.C.D of %d and %d is %d", n1, n2, gcd);
return 0;
}
Output
Enter two integers: 81 -153 GCD = 9
4.C Program to Display Fibonacci Sequence
#include <stdio.h>
int main() {
int i, n, t1 = 0, t2 = 1, nextTerm;
printf("Enter the number of terms: ");
scanf("%d", &n);
printf("Fibonacci Series: ");
for (i = 1; i <= n; ++i) {
printf("%d, ", t1);
nextTerm = t1 + t2;
t1 = t2;
t2 = nextTerm;
}
return 0;
}
Output
Enter the number of terms: 10 Fibonacci Series: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34,
5.C Program to Reverse a Number
#include <stdio.h>
int main() {
int n, rev = 0, remainder;
printf("Enter an integer: ");
scanf("%d", &n);
while (n != 0) {
remainder = n % 10;
rev = rev * 10 + remainder;
n /= 10;
}
printf("Reversed number = %d", rev);
return 0;
}
Output
Enter an integer: 1234 Reversed number = 4321
6.C Program to Check Whether a Number is Palindrome or Not
#include <stdio.h>
int main() {
int n, reversedN = 0, remainder, originalN;
printf("Enter an integer: ");
scanf("%d", &n);
originalN = n;
// reversed integer is stored in reversedN
while (n != 0) {
remainder = n % 10;
reversedN = reversedN * 10 + remainder;
n /= 10;
}
// palindrome if orignalN and reversedN are equal
if (originalN == reversedN)
printf("%d is a palindrome.", originalN);
else
printf("%d is not a palindrome.", originalN);
return 0;
}
Output
Enter an integer: 1001 1001 is a palindrome.
7.C Program to Check Whether a Number is Prime or Not
#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) {
// condition for non-prime
if (n % i == 0) {
flag = 1;
break;
}
}
if (n == 1) {
printf("1 is neither prime nor composite.");
}
else {
if (flag == 0)
printf("%d is a prime number.", n);
else
printf("%d is not a prime number.", n);
}
return 0;
}
Output
Enter a positive integer: 29 29 is a prime number.
8.C Program to Check Armstrong Number
#include <stdio.h>
int main() {
int num, originalNum, remainder, result = 0;
printf("Enter a three-digit integer: ");
scanf("%d", &num);
originalNum = num;
while (originalNum != 0) {
// remainder contains the last digit
remainder = originalNum % 10;
result += remainder * remainder * remainder;
// removing last digit from the orignal number
originalNum /= 10;
}
if (result == num)
printf("%d is an Armstrong number.", num);
else
printf("%d is not an Armstrong number.", num);
return 0;
}
Output
Enter a three-digit integer: 371 371 is an Armstrong number.
9.C Program to Calculate the Sum of Natural Numbers
#include <stdio.h>
int main() {
int n, i, sum = 0;
printf("Enter a positive integer: ");
scanf("%d", &n);
for (i = 1; i <= n; ++i) {
sum += i;
}
printf("Sum = %d", sum);
return 0;
}
Output
Enter a positive integer: 100 Sum = 5050
10.C Program to Find Factorial of a Number
#include <stdio.h>
int main() {
int n, i;
unsigned long long fact = 1;
printf("Enter an integer: ");
scanf("%d", &n);
// shows error if the user enters a negative integer
if (n < 0)
printf("Error! Factorial of a negative number doesn't exist.");
else {
for (i = 1; i <= n; ++i) {
fact *= i;
}
printf("Factorial of %d = %llu", n, fact);
}
return 0;
}
Output
Enter an integer: 10 Factorial of 10 = 3628800
think big 