printer.cpp: In function 'void add(std::__cxx11::string)':
printer.cpp:10:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(i=0;i<s.size();i++){
~^~~~~~~~~
printer.cpp:12:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j=0;j<aft[u].size();j++)
~^~~~~~~~~~~~~~
printer.cpp: In function 'void check(std::__cxx11::string)':
printer.cpp:26:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(i=0;i<s.size();i++){
~^~~~~~~~~
printer.cpp:28:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j=0;j<aft[u].size();j++)
~^~~~~~~~~~~~~~
printer.cpp: In function 'void dfs(int)':
printer.cpp:38:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0;i<V[u].size();i++){
~^~~~~~~~~~~~
printer.cpp:43:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0;i<V[u].size();i++){
~^~~~~~~~~~~~
printer.cpp: In function 'int main()':
printer.cpp:55:18: warning: format '%s' expects argument of type 'char*', but argument 2 has type 'char (*)[21]' [-Wformat=]
scanf("%s" , &s);
~~^
printer.cpp:55:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%s" , &s);
~~~~~^~~~~~~~~~~