Compilare: user.c: In function ‘main’: user.c:36:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("barbar.in", "r", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:37:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("barbar.out", "w", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:39:5: warning: ignoring return value of ‘read’, declared with attribute warn_unused_result [-Wunused-result] read(STDIN_FILENO, buf, CHUNK); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:128:35: warning: ‘in.l’ may be used uninitialized in this function [-Wmaybe-uninitialized] visited[q[qt].l][q[qt].c] = 1; ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~ user.c:128:35: warning: ‘in.c’ may be used uninitialized in this function [-Wmaybe-uninitialized]