Numbers containing 1, 2 and 3

Problem Statement - link #

Given an array arr[] of n numbers. The task is to print only those numbers whose digits are from set {1,2,3}.

Your Task: Complete findAll function and marked satisfied number as ‘1’ in the map mp in range 1 to 1000000. If no number is marked as satified number -1 will automatically be printed by the drivers code. The driver code prints the elements in sorted order.

Expected Time Complexity: O(N)
Expected Auxiliary Space: O(N)

Examples #

Example 1:

Input:
n = 3
arr[] = {4,6,7}
Output: -1
Explanation: No elements are there in the 
array which contains digits 1, 2 or 3.

Example 2:

Input:
n = 4
arr[] = {1,2,3,4}
Output: 1 2 3
Explanation: 1, 2 and 3 are the only 
elements in the array which conatins 
digits as 1, 2 or 3.

Constraints #

• 1 <= N <= 10^6
• 1 <= A[i] <= 10^6

Solutions #

class Solution{
    public:
    //Function to find all the numbers with only 1,2 and 3 in their digits.
    void findAll(int m = 0) {
        //code here
        if( 1<=m && m<=1e6 ) mp[m] = 1;
        else if(m!=0) return;
        findAll(m*10 + 1);
        findAll(m*10 + 2);
        findAll(m*10 + 3);
    }
};