Compilare: main.cpp: In function 'void solve()': main.cpp:38:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 38 | for (i = 0; i < s1.size(); i++) { | ~~^~~~~~~~~~~ main.cpp:47:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 47 | for (i = 0; i < s1.size(); i++) | ~~^~~~~~~~~~~ main.cpp:49:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 49 | for (i = 0; i < s2.size(); i++) { | ~~^~~~~~~~~~~