foo.c: In function 'main':
foo.c:7:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ^~~~~~~~~~~~~~
foo.c:10:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&a[i]);
  ^~~~~~~~~~~~~~~~~
foo.c:13:9: warning: array subscript is above array bounds [-Warray-bounds]
   temp=a[i+1];
        ~^~~~~

[Hydro](https://hydro.ac)提供评测服务