Compilare: main.cpp: In function 'int main()': main.cpp:53:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 53 | for(int j1=0; j1<a[i].size(); j1++) | ~~^~~~~~~~~~~~ main.cpp:56:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 56 | for(int j2=j1; j2<a[i].size(); j2++) | ~~^~~~~~~~~~~~ main.cpp:68:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 68 | for(int j1=0; j1<b[i].size(); j1++) | ~~^~~~~~~~~~~~ main.cpp:71:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 71 | for(int j2=j1; j2<b[i].size(); j2++) | ~~^~~~~~~~~~~~