Nth number made of prime digits

 Nth number made of prime digits

Problem Statement

Given a number 'N'. The task is to find the Nth number whose each digit is a prime number(<10) i.e 2, 3, 5, 7. In other words you have to find nth number of this sequence : 2, 3, 5, 7, 22, 23 ,.. and so on.

c++ code:

#include<bits/stdc++.h>

using namespace std;

class Solution

{

    public:

    int primeDigits(int n)

    {

        queue<int>q;

        q.push(0);

        for(int i=0;i<=n;)

        {

            int res=q.front();

            q.pop();

             i++;

            q.push((res*10)+2);

            if(i==n)break;

            i++;

            q.push((res*10)+3);

            if(i==n)break;

            i++;

            q.push((res*10)+5);

            if(i==n)break;

            i++;

            q.push((res*10)+7);

            if(i==n)break;

            

        }

        return q.back();

    }

};

int main()

{

    int t;

    cin>>t;

    while(t--)

    {

        int n;

        cin>>n;

        Solution ob;

        cout << ob.primeDigits(n) << "\n";   

    }

}