Data Type error

#1

PROBLEM: why it’s giving output 14 instead of 13.99999
CODE:
float log3(int n)
{
return log(n) / log(3);
}

bool isPowerOfThree(int num)
{ 
    cout<<log3(num)<<" ";
}
#2

Hey @yogeshcsc20
For which input ?

#3

for num input = 4782968

#4

Hey @yogeshcsc20
Try this

float x=1.999999999999;
cout<<x;

This happens because :
Precision of floating point numbers is the accuracy upto which a floating point number can hold the values after decimal.

For example 10/6 = 1.6666666… these have recurring decimals which can take infinite memory spaces to be stored.

So to avoid memory overflow in such cases the compiler set a precision limit to the number. For float values in C++ this precision is set to 6-7 digit after that if the decimal recurs it will discard the value.

#5

Is there any solution to get 13 instead of 14 as “floor(log3(4782968))” also gives me 14.

#6

try using long double instead

#7

You can also try trunc() function of c++

#8

I used double and also long double but not getting the result. But When I used log10 instead of log it worked.

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