Compilare: main.cpp: In function 'int main()': main.cpp:18:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 18 | for( i = 1; i < pattern.size(); i++ ) { | ~~^~~~~~~~~~~~~~~~ main.cpp:28:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 28 | while( i < str.size() ) { | ~~^~~~~~~~~~~~ main.cpp:31:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 31 | if( j == pattern.size() ) { | ~~^~~~~~~~~~~~~~~~~