Compilare: main.cpp: In function 'void solution()': main.cpp:34:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 34 | for(int i = 0; i < nx.size(); ++ i) | ~~^~~~~~~~~~~ main.cpp:38:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 38 | for(int j = 0; j < ny.size(); ++ j) | ~~^~~~~~~~~~~ main.cpp:42:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 42 | for(int i = 1; i < nx.size(); ++i) | ~~^~~~~~~~~~~ main.cpp:44:26: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 44 | for(int j = 1; j < ny.size(); ++ j) | ~~^~~~~~~~~~~