Compilare: user.cpp: In function ‘void getCars(int)’: user.cpp:81:17: warning: NULL used in arithmetic [-Wpointer-arith] while(*p != NULL) ^ user.cpp:83:34: warning: NULL used in arithmetic [-Wpointer-arith] while(*p == ' ' && *p != NULL) ++p; ^ user.cpp: In function ‘int main()’: user.cpp:133:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("showroom.in", "r", stdin); ^ user.cpp:134:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("showroom.out", "w", stdout); ^ user.cpp:139:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d\n", &n, &A, &R, &K); ^ user.cpp:148:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ /tmp/ccwTjq3S.o: In function `main': user.cpp:(.text.startup+0xc7): warning: the `gets' function is dangerous and should not be used.