This is very useful option indeed, just remember, that it does not work with unsigned integers and with casts

I compile with these flags and one of them turns on checking for overflows (but slows the program down too). This won't likely help you when submitting to an online judge :(

g++ -std=c++17 -Wshadow -Wall -g -fsanitize=address -fsanitize=undefined -D_GLIBCXX_DEBUG

On Codeforces, you can submit with the compiler "Clang++ 17 Diagnostics", which have much more checking than just integer overflow error. However, because test cases on Codeforces are large, you might get time limit exceeded before getting to the desired test case.

See also: Catching silly mistakes with GCC — Codeforces (including tips on how to check integer overflow, array out of bound error, check for precondition in STL algorithm, turn on warnings, etc.)

Hi, i used this pragma in my code to detect the overflow in long long int type but it is not working.. this is my code:

void overflow() {
  long long int max = numeric_limits<long long int>::max();
  long long int min = numeric_limits<long long int>::min();
  max += max;
  min -= min;
  cout << max << ":" << min;
}

is there any additional compiler flags that i have to use to detect these bugs? thanks

Fuck this thing