Compilare: user.cpp: In function ‘int main()’: user.cpp:19:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<=strlen(s[i])-1;j++) ^ user.cpp:34:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<=strlen(s[i]);j++) ^ user.cpp:67:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<=strlen(s[i])-1;j++) ^ /tmp/cctCn5m2.o: In function `main': user.cpp:(.text.startup+0xbb): warning: the `gets' function is dangerous and should not be used.