Compilare: main.cpp: In function 'std::__cxx11::string next(std::__cxx11::string)': main.cpp:9:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();++i) ~^~~~~~~~~ main.cpp:11:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(sum==s.size()){ ~~~^~~~~~~~~~ main.cpp:24:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=ind+1;i<s.size();++i) ~^~~~~~~~~ main.cpp:31:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=ind+1;i<s.size()-1;++i) ~^~~~~~~~~~~ main.cpp: In function 'std::__cxx11::string before(std::__cxx11::string)': main.cpp:40:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();++i) ~^~~~~~~~~ main.cpp:48:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(sum==s.size()){ ~~~^~~~~~~~~~ main.cpp:49:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size()-2;++i) ~^~~~~~~~~~~ main.cpp:68:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=ind0+1;i<s.size();++i) ~^~~~~~~~~ main.cpp:71:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else for(int i=0;i<s.size();++i) ~^~~~~~~~~ main.cpp:78:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=ind1+2;i<s.size();++i) ~^~~~~~~~~ main.cpp:81:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else for(int i=0;i<s.size();++i) ~^~~~~~~~~ main.cpp: In function 'int main()': main.cpp:105:16: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized] cout<<c; ^