Compilare: user.cpp: In function ‘int main()’: user.cpp:20:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(strlen(v[i])>ma) ^ user.cpp:27:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(ma==strlen(v[i])) ^ user.cpp:45:21: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] v[i][lu]=NULL; ^ user.cpp:53:34: warning: NULL used in arithmetic [-Wpointer-arith] for(l=0;v[i][l]!=NULL;l++) ^ user.cpp:55:56: warning: NULL used in arithmetic [-Wpointer-arith] while(v[i][l]!=v[j][al]&&v[j][al]!=NULL) ^ user.cpp:59:34: warning: NULL used in arithmetic [-Wpointer-arith] if(v[j][al]==NULL) ^ user.cpp:62:30: warning: NULL used in arithmetic [-Wpointer-arith] if(v[j][al]!=NULL) ^ user.cpp:73:34: warning: NULL used in arithmetic [-Wpointer-arith] for(l=0;v[i][l]!=NULL;l++) ^ user.cpp:75:56: warning: NULL used in arithmetic [-Wpointer-arith] while(v[i][l]!=v[j][al]&&v[j][al]!=NULL) ^ user.cpp:79:34: warning: NULL used in arithmetic [-Wpointer-arith] if(v[j][al]==NULL) ^ user.cpp:82:30: warning: NULL used in arithmetic [-Wpointer-arith] if(v[j][al]!=NULL) ^