Compilare: main.cpp: In function 'int main()': main.cpp:19:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 19 | for(int i = 0 ; i < s1.size() - 1 ; ++i) | ~~^~~~~~~~~~~~~~~ main.cpp:22:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 22 | for(int i = 0 ; i < s1.size() ; ++i) | ~~^~~~~~~~~~~ main.cpp:28:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 28 | for(int i = 0 ; i <= s2.size() - s1.size() ; ++i) | ~~^~~~~~~~~~~~~~~~~~~~~~~~ main.cpp:33:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 33 | for(int j = 0 ; j < s1.size() && ok; ++j) | ~~^~~~~~~~~~~