Compilare: user.cpp: In function ‘void read()’: user.cpp:8:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sir4.in", "r", stdin); ^ user.cpp:9:50: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d %d\n", &x, &a, &b, &m, &q); ^ user.cpp: In function ‘void write()’: user.cpp:44:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sir4.out", "w", stdout); ^ user.cpp:47:20: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s + 1); ^ /tmp/ccUQgpXA.o: In function `write()': user.cpp:(.text+0x2ce): warning: the `gets' function is dangerous and should not be used.