foo.cc: In function 'int main()':
foo.cc:14:6: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   14 |  if(n=3)
      |     ~^~
foo.cc:15:10: warning: unused variable 'a' [-Wunused-variable]
   15 |      int a[n];
      |          ^

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