foo.c:3:1: error: unknown type name 'bool'; did you mean '_Bool'?
 bool b[50001];
 ^~~~
 _Bool
foo.c: In function 'main':
foo.c:51:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d",&L,&n,&m);
     ^~~~~~~~~~~~~~~~~~~~~~~~
foo.c:53:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&a[i]);
     ^~~~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务