Compilare: main.cpp: In function 'int main()': main.cpp:49:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 49 | for(int f = 0 ; f < mm[k].size() ; f ++) | ~~^~~~~~~~~~~~~~ main.cpp:67:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 67 | for(int f = 0 ; f < mm[0].size() ; f ++) | ~~^~~~~~~~~~~~~~