You can run the program from the command line instead. If you really wish to run it from Dev-C++, you would need to keep the window open by pausing. One way is to wait for input, e.g.,
Code:std::cout << "Sum is " << sum << std::end1; std::cin.ignore(); // Ignore the newline character in the input buffer. std::cin.get(); // Wait for the user to press enter. return 0;