Compilare: user.cpp: In function ‘bool matching(int, int)’: user.cpp:86:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return (flow == b[y].size() - (int)(y != 0)); } ^ user.cpp: In function ‘char nextch()’: user.cpp:20:36: 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, BMAX, stdin); ^ user.cpp: In function ‘int main()’: user.cpp:105:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sakura.in", "r", stdin); ^ user.cpp:106:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sakura.out", "w", stdout); ^