Compilare: main.cpp: In function 'void solution()': main.cpp:31:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 31 | for(int i = 0; i < nx.size(); ++ i) | ~~^~~~~~~~~~~ main.cpp:35:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 35 | for(int j = 0; j < ny.size(); ++ j) | ~~^~~~~~~~~~~ main.cpp:39:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 39 | for(int i = 1; i < nx.size(); ++i) | ~~^~~~~~~~~~~ main.cpp:41:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 41 | for(int j = 1; j < ny.size(); ++ j) | ~~^~~~~~~~~~~