foo.cc: In function 'void solve(char*, int, int, char*, int, int)':
foo.cc:17:10: warning: 'root_m' may be used uninitialized in this function [-Wmaybe-uninitialized]
   17 |     solve(first, spos_f + (root_m - spos_m) + 1, epos_f, mid, root_m + 1, epos_m);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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Found 5 testcases.
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