C++ Exercises: Check whether a given number is an Ugly number or not

Last update on April 12 2025 13:00:51 (UTC/GMT +8 hours)

1. Ugly Number Check

Write a program in C++ to check whether a given number is an Ugly number or not.

Visual Presentation:

Sample Solution:

C++ Code :

# include <iostream> // Include necessary library for input and output operations
# include <string> // Include necessary library for string operations

using namespace std;

int main() {
    int n, x = 0; // Declare variables n and x, initialize x to 0
    cout << "\n\n Check whether a given number is an Ugly number:\n"; // Display message for user
    cout << "----------------------------------------------------\n";
    cout << "Input an integer number: "; // Prompt the user to input an integer number
    cin >> n; // Read user input into variable n

    if (n <= 0) {  
        cout <<"Input a correct number."; // If input is less than or equal to 0, display an error message
    }

    while (n != 1) { // Loop until n becomes 1
        if (n % 5 == 0) {  
            n /= 5; // If n is divisible by 5, divide n by 5
        } else if (n % 3 == 0) {  
            n /= 3; // If n is divisible by 3, divide n by 3
        } else if (n % 2 == 0) {  
            n /= 2; // If n is divisible by 2, divide n by 2
        } else {  
            cout <<"It is not an Ugly number."<<endl; // If none of the above conditions are met, it's not an ugly number
            x = 1; // Set x to 1 to indicate it's not an ugly number
            break; // Break out of the loop
        }  
    } 

    if (x == 0) { 
        cout <<"It is an Ugly number."<<endl; // If x is still 0, it's an ugly number
    }
    return 0; // Return 0 to indicate successful completion of the program
}

Sample Output:

Check whether a given number is an Ugly number:                       
----------------------------------------------------                   
Input an integer number: 25                                            
It is an Ugly number.

Flowchart:

For more Practice: Solve these Related Problems:

• Write a C++ program to determine if a number is ugly by testing its divisibility only by 2, 3, and 5 using recursive division.
• Write a C++ program that verifies if a number is ugly and then outputs the factorization path that leads to 1.
• Write a C++ program to check for an ugly number without using loops—employ recursion and conditional operators instead.
• Write a C++ program to read multiple numbers and print only those that are ugly by processing an array with inline functions.

C++ Code Editor:

Click to Open Editor

Contribute your code and comments through Disqus.

Previous: C++ Numbers Exercises Home
Next: Write a program in C++ to check whether a given number is Abundant or not.