- 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
Print all Good numbers in given range in C++
In this problem, we are given three values L, R, and d. Our task is to print all good numbers within the range L to R that do not contain the d as its digit.
A good number is a number in which every digit is larger than the sum of digits of its right (all less significant bits than it). For example, 732 is a good number, 7> 3+2 and 3>2.
Now, let’s take an example to understand the problem,
Input: L = 400 , R = 500 , k = 3 Output: 410, 420, 421
Explanation − good numbers between 400 to 500 are −
410, 420, 421, 430, but we cannot use 3 so 430 is not printed.
To solve this problem, for this we will check all numbers within the given range i.e. L to R, if a number is a good number and any of its digits is not equal to k, then print it otherwise leave it.
Check for Good number − we will traverse the number from right to left, and maintain a sum, at any point if the sum is greater than the next number return false.
Example
Let’s see the program to illustrate the below algorithm −
#include<bits/stdc++.h> using namespace std; bool isvalidNumber(int n, int d){ int digit = n%10; int sum = digit; if (digit == d) return false; n /= 10; while (n){ digit = n%10; if (digit == d || digit <= sum) return false; else{ sum += digit; n /= 10; } } return 1; } void printGoodNumbersLtoR(int L, int R, int d){ for (int i=L; i<=R; i++){ if (isvalidNumber(i, d)) cout << i << " "; } } int main(){ int L = 400, R = 600, d = 3; cout<<"All good numbers from "<<L<<" to "<<R<<" that do not contain "<<d<<" are :\n"; printGoodNumbersLtoR(L, R, d); return 0; }
Output
All good numbers from 400 to 600 that do not contain 3 are − 410 420 421 510 520 521 540