Compilare: user.cpp: In function ‘void read()’: user.cpp:15:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bifo.in", "r", stdin); ^ user.cpp:16:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(a + 1); ^ user.cpp:18:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(b + 1); ^ user.cpp: In function ‘void write()’: user.cpp:102:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bifo.out", "w", stdout); ^ user.cpp:103:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &m); ^ user.cpp:106:20: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(q + 1); ^ /tmp/cccD8V6M.o: In function `read()': user.cpp:(.text+0x9d): warning: the `gets' function is dangerous and should not be used.