Compilare: user.cpp: In function ‘int main()’: user.cpp:15:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<strlen(x);i++) ^ user.cpp:56:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<strlen(x);i++) ^ user.cpp:59:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=i+1;j<strlen(x);j++) ^