Compilare: user.c: In function ‘down’: user.c:43:7: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(son) ^ user.c: In function ‘main’: user.c:58:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d", &n, &M); ^ user.c:60:13: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d%d", &x, &y, &z); ^