foo.c: In function 'main':
foo.c:24:10: warning: implicit declaration of function 'abs' [-Wimplicit-function-declaration]
   24 |   b[ii]+=abs(a[ii]-a[j]);
      |          ^~~
foo.c:17:8: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   17 |  int n;scanf("%d",&n);
      |        ^~~~~~~~~~~~~~
foo.c:19:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   19 |   scanf("%d",&a[i]);
      |   ^~~~~~~~~~~~~~~~~

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