foo.cc: In function 'int main()':
foo.cc:28:22: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long long int*' [-Wformat=]
      scanf("%d",&a[i]);
                 ~~~~~^
foo.cc:27:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
     for(int i = 1;i <= n;++ i)
     ^~~
foo.cc:29:2: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
  for(int i = n;i >= 1;-- i){
  ^~~
foo.cc:26:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&c);
     ~~~~~^~~~~~~~~~~~~~
foo.cc:28:11: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
      scanf("%d",&a[i]);
      ~~~~~^~~~~~~~~~~~

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