Compilare: main.cpp: In function 'void bk(int)': main.cpp:13:8: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 13 | if(indi==a.size()){ | ~~~~^~~~~~~~~~ main.cpp:15:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 15 | for(int i=0;i<s.size();++i){ | ~^~~~~~~~~ main.cpp:20:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 20 | if(cnt==s.size()){ | ~~~^~~~~~~~~~ main.cpp:21:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 21 | for(int i=0;i<s.size();++i){ | ~^~~~~~~~~ main.cpp:28:8: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 28 | if(indi==a.size()-1){ | ~~~~^~~~~~~~~~~~ main.cpp:50:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 50 | if(frmax>=(a.size()-indi)/2+1){ | ~~~~~^~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:79:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 79 | for(int i=0;i<a.size();++i){ | ~^~~~~~~~~