Why pow(10,5) = 9,999 in C++

Question

Recently i write a block of code:

const int sections = 10;

for(int t= 0; t < 5; t++){
   int i = pow(sections, 5- t -1);  
   cout << i << en         


        

Answer 1

Whats happens is the pow function returns a double so when you do this

int i = pow(sections, 5- t -1);  

the decimal .99999 cuts of and you get 9999.

while printing directly or comparing it with 10000 is not a problem because it is runded of in a sense.

Answer 2

What happens is that your answer is actually 99.9999 and not exactly 100. This is because pow is double. So, you can fix this by using i = ceil(pow()).

Your code should be:

const int sections = 10;
for(int t= 0; t < 5; t++){
   int i = ceil(pow(sections, 5- t -1));  
   cout << i << endl;
}