Summation of a series using JavaScript

Asked Apr 11 '20 at 05:59

Active Apr 11 '20 at 06:30

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I was tackling the problem proposed on HackerRank https://www.hackerrank.com/challenges/summing-the-n-series/problem) regarding the summation of n terms. I did as follows:

 function summingSeries(n) {
    return (n*n) % (10000007);
 }

But it does not pass in some cases, would you mind telling what is wrong?

I tried doing exactly the same logic in Java and it worked, how is that even possible?

 static BigInteger summingSeries(long n) {
   BigInteger mod = BigInteger.valueOf(1000000007);

   BigInteger number = BigInteger.valueOf(n);
   BigInteger result = number.multiply(number).mod(mod);

   return result;
}

Thanks in advance

edited Apr 11 '20 at 06:30

asked Apr 11 '20 at 05:59

Matheus Minguini

"But it does not pass in some cases", what cases? – Cameron Little Apr 11 '20 at 06:02
Also see https://stackoverflow.com/a/3439981/2178159 – Cameron Little Apr 11 '20 at 06:04
When n = 681519110 – Matheus Minguini Apr 11 '20 at 06:04
It has to do with integer overflow in javascript, see https://stackoverflow.com/questions/929910/modulo-in-javascript-large-number – Cameron Little Apr 11 '20 at 06:11
Thanks, I really didn't know that, I just spent two hours reviewing the code and my Maths :/ – Matheus Minguini Apr 11 '20 at 06:17
You should also use correct object type to large numbers calculations, `BigNumber` this case. – Jsowa Apr 11 '20 at 16:55

Summation of a series using JavaScript

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