C++ Program for Smallest K digit number divisible by X

Integers X and K are given. The task is to find the smallest K-digit number divisible by X.

Examples:

Input : X = 83, K = 5
Output : 10043
10040 is the smallest 5 digit
number that is multiple of 83.

Input : X = 5, K = 2
Output : 10

An efficient solution would be :

Compute MIN : smallest K-digit number (1000...K-times)
If, MIN % X is 0, ans = MIN
else, ans = (MIN + X) - ((MIN + X) % X))
This is because there will be a number in 
range [MIN...MIN+X] divisible by X.
filter_none

edit
close

play_arrow

link
brightness_4
code

// CPP code to find smallest K-digit number
// divisible by X
#include <bits/stdc++.h>
using namespace std;
  
// Function to compute the result
int answer(int X, int K)
{
    // Computing MIN
    int MIN = pow(10, K - 1);
  
    // MIN is the result
    if (MIN % X == 0)
        return MIN;
  
    // returning ans
    return ((MIN + X) - ((MIN + X) % X));
}
  
// Driver
int main()
{
    // Number whose divisible is to be found
    int X = 83;
  
    // Max K-digit divisible is to be found
    int K = 5;
  
    cout << answer(X, K);
}

chevron_right


Output:

10043

Please refer complete article on Smallest K digit number divisible by X for more details!



My Personal Notes arrow_drop_up


Article Tags :
Practice Tags :


Be the First to upvote.


Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.