Compilare: main.cpp: In function 'std::vector<int> find_pi(const std::string&)': main.cpp:7:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 7 | for (int i = 1; i < s.length(); i++) { | ~~^~~~~~~~~~~~ main.cpp: In function 'std::vector<int> find_z(const std::string&)': main.cpp:24:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 24 | for (int i = 0; i < s.length(); i++) { | ~~^~~~~~~~~~~~ main.cpp:29:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 29 | while (i + z[i] < s.length() && s[z[i]] == s[i + z[i]]) { | ~~~~~~~~~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:57:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 57 | while (3 * ans > s.length()) { | ~~~~~~~~^~~~~~~~~~~~ main.cpp:67:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 67 | for (int i = ans; i <= s.length() - 2 * ans; i++) { | ~~^~~~~~~~~~~~~~~~~~~~~~~ main.cpp:82:46: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 82 | for (int i = s.length() - 2 * ans + 1; i <= s.length() - 2 * next; i++) { | ~~^~~~~~~~~~~~~~~~~~~~~~~~