Compilare: user.cpp: In function ‘int main()’: user.cpp:126:12: warning: variable ‘m’ set but not used [-Wunused-but-set-variable] int n, m, x, i, y, root; ^ user.cpp: In function ‘char nextch()’: user.cpp:14:37: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, BUF_SIZE, 1, fin); ^