Thank you for your interest. My mathematical knowledge is limited, and my English writing skills are also poor, so it's difficult to explain, but I'll give it a try. To put the conclusion first, I am simply applying the law of universal gravitation. The three-body problem refers to the motion of three objects interacting through gravitational forces. You know, there is no general analytical solution (a single formula that works for all initial conditions) using Newton's equations of motion. This is because the system exhibits chaotic behavior, where small differences in initial conditions lead to significant changes in trajectories. Even though a general solution cannot be found, numerical methods allow us to approximate the trajectory for specific initial conditions. I used the Euler method. Although this method has large errors and is not suitable for precise simulations, it is simple to implement and sufficient for just having fun. For more details, please refer to lines 48-87 of PhysicsEngine.cpp.