Compilare: main.c: In function 'main': main.c:19:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("dfs.in","r",stdin); ^~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:20:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("dfs.out","w",stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:21:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^~~~~~~~~~~~~~~~~~~~ main.c:24:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^~~~~~~~~~~~~~~~~~~~ main.c:34:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^~~~~~~~~~~~~~~~~~~~ main.c:37:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^~~~~~~~~~~~~~~~~~~~