Invalid product of two INT_MAX numbes in C / C ++

Question

In my case, the product of two INT_MAX numbers is equal 296447233, which is wrong.

long long int product = 0;
product = 2137483647 * 2137483647;
printf("product: %lli\n", product);

What am I doing wrong and how to fix it ?? Thank!

Answer 1

Both of 2137483647are of type int. Thus, they retain this type and overflow.

Make them long longs:

product = 2137483647LL * 2137483647LL;

or cast:

product = (long long)2137483647 * 2137483647;

Answer 2

Try

product = 2137483647LL * 2137483647LL; 

for the compiler to process numbers for how long are long