Compilare: main.cpp: In function 'void Insert(std::string)': main.cpp:23:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 23 | for(int i = 0;i < a.size(); ++i) | ~~^~~~~~~~~~ main.cpp: In function 'void Delete(std::string)': main.cpp:42:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 42 | for(int i = 0;i < a.size(); ++i) | ~~^~~~~~~~~~ main.cpp:49:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 49 | for(int i = 0;i < a.size(); ++i) | ~~^~~~~~~~~~ main.cpp:41:15: warning: unused variable 'cnt' [-Wunused-variable] 41 | int s = 0,cnt = 0; | ^~~ main.cpp: In function 'int Occur(std::string)': main.cpp:59:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 59 | for(int i = 0;i < a.size(); ++i) | ~~^~~~~~~~~~ main.cpp: In function 'int prefix(std::string)': main.cpp:72:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 72 | for(int i = 0;i < a.size(); ++i) | ~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:90:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 90 | for(int j = 2;j < s.size(); ++j) | ~~^~~~~~~~~~