Confusion with a while statement evaluating if a number is triangular
- by Darkkurama
I've been having troubles trying to figure out how to solve a function. I've been assigned the development of a little programme which tells if a number is "triangular" (a number is triangular when the addition of certain consecutive numbers in the [1,n] interval is n. Following the definition, the number 10 is triangular, because in the [1,10] interval, 1+2+3+4=10).
I've coded this so far:
class TriangularNumber{
boolean numTriangular(int n) {
boolean triangular = false;
int i = n;
while(n>=0 && triangular){
//UE06 is a class which contains the function "f0", which makes the addition of all the numbers in a determined interval
UE06 p = new UE06();
if ((p.f0(1, i))==n)
triangular = true;
else
i=i-1;
}
return triangular;
}
boolean testTriangular = numTriangular(10) == true &&
numTriangular(7) == false &&
numTriangular(6) == true;
public static void main(String[] args){
TriangularNumber p = new TriangularNumber();
System.out.println("testTriangular = " + p.testTriangular);
}
}
According to those boolean tests I made, the function is wrong. As I see the function, it goes like this:
I state that the input number in the initial state isn't triangular
(triangular=false) and i=n (determining the interval [1,i] where the
function is going to be evaluated
While n is greater or equals 0 and the number isn't triangular, the
loop starts
The loop goes like this: if the addition of all the numbers in the
[1,i] interval is n, the number is triangular, causing the loop to
end. If that statement is false, i goes from i to (i-1), starting
the loop again with that particular interval, and so on till the
addition is n.
I can't spot the error in my "algorithm", any advice?
Thanks!
