Compilare: main.cpp: In function 'int main()': main.cpp:22:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 22 | for(int i = 0; i < s.size(); i++) { | ~~^~~~~~~~~~ main.cpp:26:44: warning: comparison of integer expressions of different signedness: 'int64_t' {aka 'long int'} and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 26 | while(st > 0 && dr < s.size() - 1 && s[st - 1] == s[dr + 1]) { | ~~~^~~~~~~~~~~~~~ main.cpp:47:52: warning: comparison of integer expressions of different signedness: 'int64_t' {aka 'long int'} and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 47 | while(st > 0 && dr < s.size() - 1 && s[st - 1] == s[dr + 1]) { | ~~~^~~~~~~~~~~~~~ main.cpp:58:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 58 | for(int i = 0; i < s.size(); i ++) | ~~^~~~~~~~~~