C++ Codes - Basic to Advanced 💻

#Digits #Algorithms

Count the number of digits in a number

#include <iostream>

int countDigits(int n) {
    if (n == 0) {
        return 1;
    }
    int count = 0;
    while (n != 0) {
        n /= 10;
        count++;
    }
    return count;
}

int main() {
    int number = 12345;
    int digitCount = countDigits(number);
    std::cout << "Number of digits: " << digitCount << std::endl;
    return 0;
}

#PrimeNumbers #Algorithm #NumberTheory

Print prime numbers in a given range

#include <iostream>
#include <cmath>

bool isPrime(int n) {
    if (n <= 1) return false;
    for (int i = 2; i <= sqrt(n); i++) {
        if (n % i == 0) return false;
    }
    return true;
}

int main() {
    int start, end;
    std::cin >> start >> end;

    for (int i = start; i <= end; i++) {
        if (isPrime(i)) {
            std::cout << i << " ";
        }
    }
    std::cout << std::endl;
    return 0;
}

#GCD #EuclideanAlgorithm #Algorithms

Find GCD of two numbers using loop

#include <iostream>

int gcd(int a, int b) {
    while (b != 0) {
        int temp = b;
        b = a % b;
        a = temp;
    }
    return a;
}

int main() {
    int num1, num2;
    std::cout << "Enter two integers: ";
    std::cin >> num1 >> num2;
    std::cout << "GCD of " << num1 << " and " << num2 << " is " << gcd(num1, num2) << std::endl;
    return 0;
}

#Cpp #Multiplication #Table

Print multiplication table of a number

#include <iostream>

int main() {
    int num;
    std::cout << "Enter an integer: ";
    std::cin >> num;

    for (int i = 1; i <= 10; ++i) {
        std::cout << num << " * " << i << " = " << num * i << std::endl;
    }

    return 0;
}

#Fibonacci #Algorithms #Coding

Generate Fibonacci series up to N terms

#include <iostream>

int main() {
    int n;
    std::cout << "Enter the number of terms: ";
    std::cin >> n;

    int a = 0, b = 1;

    if (n <= 0) {
        std::cout << "Invalid input. Please enter a positive integer.";
        return 1;
    }

    std::cout << "Fibonacci Series: ";
    for (int i = 1; i <= n; ++i) {
        std::cout << a << " ";
        int nextTerm = a + b;
        a = b;
        b = nextTerm;
    }
    std::cout << std::endl;
    return 0;
}

#PalindromeCheck #Looping #MathCoding

Check if a number is palindrome using loop

#include <iostream>

using namespace std;

bool isPalindrome(int num) {
    int originalNum = num;
    int reversedNum = 0;

    while (num > 0) {
        int lastDigit = num % 10;
        reversedNum = (reversedNum * 10) + lastDigit;
        num /= 10;
    }

    return originalNum == reversedNum;
}

int main() {
    int number;
    cout << "Enter a number: ";
    cin >> number;

    if (isPalindrome(number)) {
        cout << number << " is a palindrome." << endl;
    } else {
        cout << number << " is not a palindrome." << endl;
    }

    return 0;
}

#NumberReversal #WhileLoop #CodingInterview

Reverse a number using while loop

#include <iostream>

int main() {
    int n, reversed_n = 0, remainder;
    std::cout << "Enter an integer: ";
    std::cin >> n;

    while (n != 0) {
        remainder = n % 10;
        reversed_n = reversed_n * 10 + remainder;
        n /= 10;
    }

    std::cout << "Reversed Number = " << reversed_n << std::endl;
    return 0;
}

#DigitsSum #Algorithm

Sum of digits of a number

#include <iostream>

int sumOfDigits(int n) {
    int sum = 0;
    while (n > 0) {
        sum += n % 10;
        n /= 10;
    }
    return sum;
}

int main() {
    int num;
    std::cout << "Enter a number: ";
    std::cin >> num;
    std::cout << "Sum of digits: " << sumOfDigits(num) << std::endl;
    return 0;
}

#Factorial #WhileLoop #Cpp

Calculate factorial of a number using while loop

#include <iostream>

int factorial(int n) {
    if (n < 0) {
        return -1; // Indicate an error for negative input
    }
    int result = 1;
    while (n > 0) {
        result *= n;
        n--;
    }
    return result;
}

int main() {
    int num = 5;
    int fact = factorial(num);
    if (fact != -1) {
        std::cout << "Factorial of " << num << " is " << fact << std::endl;
    } else {
        std::cout << "Factorial is not defined for negative numbers." << std::endl;
    }
    return 0;
}

#Loops #NaturalNumbers #Programming

Print all natural numbers up to N using for loop

#include <iostream>

int main() {
  int n;
  std::cout << "Enter a positive integer: ";
  std::cin >> n;

  if (n <= 0) {
    std::cout << "Please enter a positive integer.\n";
    return 1; 
  }

  for (int i = 1; i <= n; ++i) {
    std::cout << i << " ";
  }
  std::cout << std::endl;

  return 0;
}