Compilare: main.cpp: In function 'int main()': main.cpp:62:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 62 | for(int i=0;i<lines.size();i++) | ~^~~~~~~~~~~~~ main.cpp:79:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 79 | for(int j=i+1;j<lines.size();j++) | ~^~~~~~~~~~~~~ main.cpp:111:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 111 | for(int j=i+1;j<lines.size();j++) | ~^~~~~~~~~~~~~ main.cpp:132:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 132 | for(int i=0;i<lines.size();i++) | ~^~~~~~~~~~~~~ main.cpp:150:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 150 | for(int j=0;j<col.size();j++) | ~^~~~~~~~~~~