Compilare: main.cpp: In function 'int main()': main.cpp:61:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sdo.in", "r", stdin); ^ main.cpp:62:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sdo.out", "w", stdout); ^ main.cpp: In function 'void read(int&)': main.cpp:18:49: 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, buff_size, stdin), pos = 0; ^ main.cpp:24:48: 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, buff_size, stdin), pos = 0; ^