Compilare: user.cpp: In function ‘void read()’: user.cpp:23:35: 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:24:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(a + 1); ^ user.cpp:25:16: 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:128:37: 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:129:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &m); ^ user.cpp:132:20: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(q + 1); ^ user.cpp: In function ‘char solve()’: user.cpp:124:17: warning: ‘j’ may be used uninitialized in this function [-Wmaybe-uninitialized] return chs(j); ^ /tmp/ccZZ1XPe.o: In function `read()': user.cpp:(.text+0xf0): warning: the `gets' function is dangerous and should not be used.