Compilare: main.cpp: In function 'void solve()': main.cpp:34:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 34 | if(j < s1.length()) | ~~^~~~~~~~~~~~~ main.cpp:48:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 48 | if(j < s2.length()) | ~~^~~~~~~~~~~~~ main.cpp:62:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 62 | if(j < s3.length()) | ~~^~~~~~~~~~~~~ main.cpp:76:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 76 | if(j < s4.length()) | ~~^~~~~~~~~~~~~