Print first k digits of 1/n where n is a positive integer

Given a positive integer n, print first k digits after point in value of 1/n. Your program should avoid overflow and floating point arithmetic.

Examples:

Input:   n = 3, k = 3
Output:  333

Input:   n = 50, k = 4
Output:  0200

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Let us consider an example n = 7, k = 3. The first digit of 1/7 is ‘1’, it can be obtained by doing integer value of 10/7. Remainder of 10/7 is 3. Next digit is 4 which can be obtained by taking integer value of 30/7. Remainder of 30/7 is 2. Next digits is 2 which can be obtained by taking integer value of 20/7

#include <iostream>
using namespace std;

// Function to print first k digits after dot in value
// of 1/n.  n is assumed to be a positive integer.
void print(int n, int k)
{
   int rem = 1; // Initialize remainder

   // Run a loop k times to print k digits
   for (int i = 0; i < k; i++)
   {
         // The next digit can always be obtained as
         // doing (10*rem)/10
         cout << (10 * rem) / n;

         // Update remainder
         rem = (10*rem) % n;
   }
}

// Driver program to test above function
int main()
{
    int n = 7, k = 3;
    print(n, k);
    cout << endl;

    n = 21, k = 4;
    print(n, k);

    return 0;
}

Output:

142
0476

Reference:
Algorithms And Programming: Problems And Solutions by Alexander Shen

This article is contributed by Sachin. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.


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