Compilare: main.cpp: In function 'int main()': main.cpp:60:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 60 | for(int i=0;i<lines.size();i++) | ~^~~~~~~~~~~~~ main.cpp:76:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 76 | for(int j=i+1;j<lines.size();j++) | ~^~~~~~~~~~~~~ main.cpp:93:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 93 | for(int i=0;i<lines.size();i++) | ~^~~~~~~~~~~~~ main.cpp:103:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 103 | for(int i=0;i<col.size();i++) | ~^~~~~~~~~~~ main.cpp:121:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 121 | for(int j=i+1;j<col.size();j++) | ~^~~~~~~~~~~