Compilare: user.cpp: In function ‘void expresie()’: user.cpp:9:25: warning: NULL used in arithmetic [-Wpointer-arith] while(*c!='\n'&&*c!=NULL) ^ user.cpp: In function ‘int main()’: user.cpp:120:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bool.in", "r", stdin); ^ user.cpp:121:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bool.out", "w", stdout); ^ user.cpp:124:13: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(si); ^ user.cpp:126:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &n); ^ user.cpp:131:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &f); ^ /tmp/ccM7KDG0.o: In function `main': user.cpp:(.text.startup+0x63): warning: the `gets' function is dangerous and should not be used.