foo.cc: In function 'int main()':
foo.cc:23:5: warning: variable 'l' set but not used [-Wunused-but-set-variable]
 int l,r,d,t;
     ^
foo.cc:23:9: warning: unused variable 'd' [-Wunused-variable]
 int l,r,d,t;
         ^
foo.cc:23:11: warning: unused variable 't' [-Wunused-variable]
 int l,r,d,t;
           ^
foo.cc:10:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 scanf("%d%d",&n,&q);
 ~~~~~^~~~~~~~~~~~~~
foo.cc:15:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 scanf("%d",&a[i]);
 ~~~~~^~~~~~~~~~~~
foo.cc:49:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 scanf("%d",&r);
 ~~~~~^~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务