Question

Write a program in C++ to reverse a positive integer number input from the keyboard.

Answer 1

#include <iostream>
using namespace std;

int main() {
    long long n, rev = 0;
    
    cout << "Enter a positive integer: ";
    cin >> n;

    // The loop runs as long as n is greater than 0
    while (n > 0) {
        int digit = n % 10;      // Get the last digit
        rev = rev * 10 + digit;  // Shift rev left and add the digit
        n /= 10;                 // Remove the last digit from n
    }

    cout << "Reversed number: " << rev << endl;
    
    return 0;
}