Compilare: main.cpp: In function 'void calcPi()': main.cpp:13:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 13 | for(int i=1;i<pat.size();i++){ | ~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:28:18: 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<b.size();i++){ | ~^~~~~~~~~ main.cpp:33:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 33 | if(j == pat.size()){ | ~~^~~~~~~~~~~~~