foo.cc: In function 'int main()':
foo.cc:139:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  139 |   scanf("%d",&n);getline(cin,b[0]);
      |   ~~~~~^~~~~~~~~
foo.cc: In function 'void hash1()':
foo.cc:57:43: warning: 'opt' may be used uninitialized in this function [-Wmaybe-uninitialized]
   57 |     topopt++;st[topopt]=a[i];stopt[topopt]=opt;
      |                              ~~~~~~~~~~~~~^~~~
foo.cc: In function 'void hash2(int)':
foo.cc:118:46: warning: 'opt' may be used uninitialized in this function [-Wmaybe-uninitialized]
  118 |     topopt++;st[topopt]=b[k][i];stopt[topopt]=opt;
      |                                 ~~~~~~~~~~~~~^~~~

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