Compilare: main.cpp: In function 'void read(int&)': main.cpp:35:39: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(ch, 1, bsize, stdin); ^ main.cpp:47:39: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(ch, 1, bsize, stdin); ^ main.cpp: In function 'int main()': main.cpp:113:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("deletegcd.in", "r", stdin); ^ main.cpp:114:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("deletegcd.out", "w", stdout); ^ main.cpp:117:31: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(ch, 1, bsize, stdin); ^