Compilare: user.cpp: In function ‘void build_automaton()’: user.cpp:16:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<strlen(a)) ~^~~~~~~~~~ user.cpp: In function ‘int kmp()’: user.cpp:38:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<strlen(b);i++) ~^~~~~~~~~~ user.cpp:40:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j == strlen(a)-1) ~~^~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:58:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<pos_holder.size();i++) ~^~~~~~~~~~~~~~~~~~