Compilare: main.cpp: In function 'int main()': main.cpp:20:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 20 | while(j < s[i - 1].length() && j < s[i].length() && s[i - 1][j] == s[i][j]) | ~~^~~~~~~~~~~~~~~~~~~ main.cpp:20:42: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 20 | while(j < s[i - 1].length() && j < s[i].length() && s[i - 1][j] == s[i][j]) | ~~^~~~~~~~~~~~~~~