foo.cc: In function 'int main()':
foo.cc:104:11: warning: statement has no effect [-Wunused-value]
  104 |     for ( p;p<a+n;p++)  {cin>>*p;}
      |           ^
foo.cc:101:19: warning: unused variable 'cnt' [-Wunused-variable]
  101 |         int n;int cnt=0;
      |                   ^~~

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