Compilare: user.cpp: In function ‘int main()’: user.cpp:13:13: warning: ISO C++ forbids converting a string constant to ‘char*’ [-Wwrite-strings] strcat(" ",a); ^ user.cpp:14:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<strlen(a);i++) ^ user.cpp:16:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<strlen(a);i++) ^