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The following function isNiven( ) is a part of some class which is used to check if a given number…
The following function isNiven( ) is a part of some class which is used to check if a given number is a Niven number or not. There are some places in the code marked by ?1? , ?2? , ?3? which may be replaced by a statement / expression so that the function works properly.
A Niven number is a number which is exactly divisible by the sum of its digits.
Example: 120 = 1+2+0 = 3 and 120 is exactly divisible by 3
boolean isNiven(int n)
{
int sum = 0, temp = ?1?;
while (temp > 0)
{
sum += ?2?;
temp /= 10;
}
return (?3?);
}Answer
Answer
AI?1? = $n$ — initialise temp with n, the number whose digit sum is to be found.
?2? = $temp \% 10$ — adds the last (units) digit of temp to sum.
?3? = $(sum \ne 0\ \&\&\ n \% sum == 0)$ — true only when n is exactly divisible by the digit sum (and sum is non-zero, to avoid division by zero).
(Verified by running the completed function: isNiven(120) returns true, isNiven(123) returns false.)
From ISC 2026 Improvement Computer Science Paper 1, question 2(iv).