foo.cc: In function 'int main()':
foo.cc:16:11: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
    if(a[i]=a[i+1])
       ~~~~^~~~~~~
foo.cc:6:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
foo.cc:9:7: 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