foo.c: In function 'Insert':
foo.c:8:4: error: 'i' undeclared (first use in this function)
  a[i+1]=x;
    ^
foo.c:8:4: note: each undeclared identifier is reported only once for each function it appears in
foo.c: In function 'main':
foo.c:18:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ^~~~~~~~~~~~~~
foo.c:20:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a[i]);
   ^~~~~~~~~~~~~~~~~~
foo.c:21:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &x);
  ^~~~~~~~~~~~~~~

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