Compilare: user.cpp: In function ‘int main()’: user.cpp:76:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("transport2.in", "r", stdin); ^ user.cpp:77:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("transport2.out", "w", stdout); ^ user.cpp:81:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &n, &m); ^ user.cpp:85:19: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(buff); ^ /tmp/ccxwNvMp.o: In function `main': user.cpp:(.text.startup+0x92): warning: the `gets' function is dangerous and should not be used.