Compilare: user.cpp: In function ‘int main()’: user.cpp:80:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("parb.in", "r", stdin); ^ user.cpp:81:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("parb.out", "w", stdout); ^ user.cpp:83:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &N); ^ user.cpp:84:19: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(Symbol + 1); ^ user.cpp:89:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &u, &v); ^ /tmp/ccef9aS6.o: In function `main': user.cpp:(.text.startup+0x67): warning: the `gets' function is dangerous and should not be used.