Disarium Number - GeeksforGeeks

Given a number “n”, find if it is Disarium or not. A number is called Disarium if sum of its digits powered with their respective positions is equal to the number itself.

Examples:

Input   : n = 135
Output  : Yes 
1^1 + 3^2 + 5^3 = 135
Therefore, 135 is a Disarium number

Input   : n = 89
Output  : Yes 
8^1+9^2 = 89
Therefore, 89 is a Disarium number

Input   : n = 80
Output  : No
8^1 + 0^2 = 8

Recommended: Please solve it on “PRACTICE” first, before moving on to the solution.

The idea is to fist count digits in given numbers. Once we have count, we traverse all digits from right most (using % operator), raise its power to digit count and decrement the digit count.

Below is implementation of above idea.

C++

// C++ program to check whether a number is Desoriam 
// or not 
#include<bits/stdc++.h> 
using namespace std; 
  
// Finds count of digits in n 
int countDigits(int n) 
{ 
    int count_digits = 0; 
  
    // Count number of digits in n 
    int x = n; 
    while (x) 
    { 
        x = x/10; 
  
        // Count the no. of digits 
        count_digits++; 
    } 
    return count_digits; 
} 
  
// Function to check whether a number is disarium or not 
bool check(int n) 
{ 
    // Count digits in n. 
    int count_digits = countDigits(n); 
  
    // Compute sum of terms like digit multiplied by 
    // power of position 
    int sum = 0; // Initialize sum of terms 
    int x = n; 
    while (x) 
    { 
        // Get the rightmost digit 
        int r = x%10; 
  
        // Sum the digits by powering according to 
        // the positions 
        sum = sum + pow(r, count_digits--); 
        x = x/10; 
    } 
  
    // If sum is same as number, then number is 
    return (sum == n); 
} 
  
//Driver code to check if number is disarium or not 
int main() 
{ 
    int n = 135; 
    if( check(n)) 
        cout << "Disarium Number"; 
    else
        cout << "Not a Disarium Number"; 
    return 0; 
} 

Java

// Java program to check whether a number is Desoriam 
// or not 
  
class Test 
{ 
    // Method to check whether a number is disarium or not 
    static boolean check(int n) 
    { 
        // Count digits in n. 
        int count_digits = Integer.toString(n).length(); 
       
        // Compute sum of terms like digit multiplied by 
        // power of position 
        int sum = 0; // Initialize sum of terms 
        int x = n; 
        while (x!=0) 
        { 
            // Get the rightmost digit 
            int r = x%10; 
       
            // Sum the digits by powering according to 
            // the positions 
            sum = (int) (sum + Math.pow(r, count_digits--)); 
            x = x/10; 
        } 
       
        // If sum is same as number, then number is 
        return (sum == n); 
    } 
      
    // Driver method 
    public static void main(String[] args)  
    { 
        int n = 135; 
          
        System.out.println(check(n) ? "Disarium Number" : "Not a Disarium Number"); 
    } 
} 

Python

# Python program to check whether a number is Desarium 
# or not 
import math  
  
# Method to check whether a number is disarium or not 
def check(n) : 
  
    # Count digits in n. 
    count_digits = len(str(n)) 
       
    # Compute sum of terms like digit multiplied by 
    # power of position 
    sum = 0  # Initialize sum of terms 
    x = n 
    while (x!=0) : 
  
        # Get the rightmost digit 
        r = x % 10
           
        # Sum the digits by powering according to 
        # the positions 
        sum = (int) (sum + math.pow(r, count_digits)) 
        count_digits = count_digits - 1
        x = x/10
         
    # If sum is same as number, then number is 
    if sum == n : 
        return 1
    else : 
        return 0
        
# Driver method 
n = 135
if (check(n) == 1) : 
    print "Disarium Number"
else : 
    print "Not a Disarium Number"
   
# This code is contributed by Nikita Tiwari. 

Output:

Disarium Number

This article is contributed by Sahil Chhabra(KILLER). If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

My Personal Notes

Recommended: Please solve it on “PRACTICE” first, before moving on to the solution.

C++

Java

Python

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