Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Find a number x such that sum of x and its digits is equal to given n in C++
Here we will see one problem, where we take a number n, we have to find another value say x, such that x + digit sum of x is same as the given number n. Suppose the value of n is 21. This program will return a number x = 15, as 15 + digit sum of 15, i.e. 15 + 1 + 5 = 21 = n.
To solve this problem, we have to follow simple approach. We will iterate through 1 to n, in each iteration, we will see if the sum of the number and its digit sum is same as the number, then stop, otherwise continue.
Example
#include<iostream>
using namespace std;
int getDigitSum(int n) {
int sum = 0;
while (n) {
sum += n % 10;
n /= 10;
}
return sum;
}
int getNumber(int n) {
for (int i = 0; i <= n; i++)
if (i + getDigitSum(i) == n)
return i;
return -1;
}
int main() {
int n = 21;
cout << "The value of x is: " << getNumber(n);
}Output
The value of x is: 15
Updated on: 24-Oct-2019
222 Views
Advertisements