foo.c: In function 'main':
foo.c:19:11: error: 't' undeclared (first use in this function)
   19 |     qsort(t,m,sizeof(int),compare);
      |           ^
foo.c:19:11: note: each undeclared identifier is reported only once for each function it appears in
foo.c:31:5: error: 'cout' undeclared (first use in this function)
   31 |     cout<<ans;
      |     ^~~~

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