Compilare: main.cpp: In function 'int main()': main.cpp:44:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<strlen(c)) ~^~~~~~~~~~ main.cpp:46:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<strlen(c) && isalpha(c[i])==0) ~^~~~~~~~~~ main.cpp:48:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<strlen(c) && isalpha(c[i])!=0) ~^~~~~~~~~~ main.cpp:83:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[k].size();i++) ~^~~~~~~~~~~~