Compilare: user.cpp: In function ‘int main()’: user.cpp:41:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ninjago.in", "r", stdin); ^ user.cpp:42:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ninjago.out", "w", stdout); ^ user.cpp:44:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n%d %d\n", &type, &n, &m); ^ user.cpp:47:66: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &x[i].second.first, &x[i].second.second); ^ user.cpp:48:56: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s + 1), N = strlen(s + 1), put = 1, ok = 0; ^ /tmp/ccBxAf7u.o: In function `main': user.cpp:(.text.startup+0xba): warning: the `gets' function is dangerous and should not be used.