Compilare: user.cpp: In function ‘int main()’: user.cpp:18:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<strlen(x);i++) ^ user.cpp:30:87: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(z[0]=='.' || z[0]=='!' || z[0]=='?' || z[0]==' ')for(int i=0;i<=strlen(z);i++)z[i]=z[i+1]; ^