Print all Jumping Numbers smaller than or equal to a given value in C++

In this problem, we are given a number n and we have to print all jumping numbers that are smaller than or equal to n.

Jumping Numbers are the number whose adjacent digits differ by one only. Some jumping numbers are 4565, 98, 7. All single-digit numbers are considered as jumping numbers. 235 is not a jumping number.

Now, let’ take an example to understand the problem

Input: N = 32
Output: 0 1 2 3 4 5 6 7 8 9 10 12 21 23 32

To solve this problem, we will assume a graph where 0 is the starting node and traverse it to all reachable nodes. You can traverse it using BFS or DFS. This graph is created using a condition that makes values jumping numbers.

Example

The below code implements our solution −

 Live Demo

#include <bits/stdc++.h>
using namespace std;
void traverse(int N, int num) {
   queue<int> q;
   q.push(num);
   while (!q.empty()) {
      num = q.front();
      q.pop();
      if (num <= N) {
         cout << num << " ";
         int last_dig = num % 10;
         if (last_dig == 0)
            q.push((num * 10) + (last_dig + 1));
         else if (last_dig == 9)
            q.push((num * 10) + (last_dig - 1));
         else {
            q.push((num * 10) + (last_dig - 1));
            q.push((num * 10) + (last_dig + 1));
         }
      }
   }
}
void printJumpingNumber(int N) {
   cout<<0<<" ";
   for (int i = 1; i <= 9 && i <= N; i++)
   traverse(N, i);
}
int main() {
   int N = 54;
   cout<<"Jumping Numbers less than "<<N<<" are :\n";
   printJumpingNumber(N);
   return 0;
}

Output

Jumping Numbers less than 54 are −
0 1 10 12 2 21 23 3 32 34 4 43 45 5 54 6 7 8 9