Compilare: main.cpp: In function 'int main()': main.cpp:30:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<std::pair<int, int>, std::pair<int, int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 30 | for(int j = 0; j < v.size() && !found; ++j) | ~~^~~~~~~~~~