Compilare: user.cpp: In function ‘void do2()’: user.cpp:74:9: warning: unused variable ‘cnt’ [-Wunused-variable] int cnt = 0; ^ user.cpp: In function ‘void read(int&)’: user.cpp:36:46: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, Mx, stdin), pos = 0; ^ user.cpp:43:46: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, Mx, stdin), pos = 0; ^ user.cpp: In function ‘int main()’: user.cpp:107:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dragoni.in", "r", stdin); ^ user.cpp:108:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dragoni.out", "w", stdout); ^