foo.c: In function 'main':
foo.c:7:2: error: variable-sized object may not be initialized
  int a[n]={0};
  ^~~
foo.c:7:12: warning: excess elements in array initializer
  int a[n]={0};
            ^
foo.c:7:12: note: (near initialization for 'a')
foo.c: In function 'insert':
foo.c:22:16: warning: unused variable 'y' [-Wunused-variable]
    int x=i;int y;
                ^
foo.c: In function 'main':
foo.c:6:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ^~~~~~~~~~~~~~
foo.c:9:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&a[i]);
   ^~~~~~~~~~~~~~~~~
foo.c:10:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&k);
  ^~~~~~~~~~~~~~
foo.c: In function 'insert':
foo.c:28:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

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