Compilare: main.cpp: In function 'int main()': main.cpp:12:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 12 | for(i=0;i<s.size();i++){ | ~^~~~~~~~~ main.cpp:24:29: warning: operation on 'k' may be undefined [-Wsequence-point] 24 | st[k++]=st[k-1]; | ~^~ main.cpp:24:29: warning: operation on 'k' may be undefined [-Wsequence-point] main.cpp:46:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 46 | for(i=0;i<s.size();i++){ | ~^~~~~~~~~