Compilare: main.cpp: In function 'int main()': main.cpp:30:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 30 | if(x1 < mat[lin].size()) | ~~~^~~~~~~~~~~~~~~~~ main.cpp:33:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 33 | if(x2 >= mat[lin].size()) | ~~~^~~~~~~~~~~~~~~~~~ main.cpp:44:26: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 44 | if(mat[i].size() <= c) | ~~~~~~~~~~~~~~^~~~