foo.cc: In function 'void dts::main()':
foo.cc:21:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d",&T);
         ~~~~~^~~~~~~~~
foo.cc:24:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d",&n);
             ~~~~~^~~~~~~~~
foo.cc:26:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
                 scanf("%d",&a[i]);
                 ~~~~~^~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务