Code breaks when running

Question

This code crashes / exits out when running. I suspect a vector out-of-bounds logical error. Can you guys help me fix it? ( Well if you have a SFML compiler ofc )
https://sololearn.com/compiler-playground/cNXx0QIpQ4R6/?ref=app

Answer 1

Nvm I found out why;
I needed to initialize the vectors:
std::vector<std::vector<int>> lifeT(TRAIL_LENGTH);

std::vector<sf::Vector2f> vel(NUM_OF_SNAKES);

And

std::vector<std::vector<sf::Vector2f>> rPos(NUM_OF_SNAKES);