Fix formatting and assertion in wavelet_matrix.hpp

Author: lrvideckis

library/data_structures_[l,r)/seg_tree_uncommon/wavelet_matrix.hpp

@@ -18,6 +18,8 @@ struct wavelet_matrix {
       vector<bool> b(n);
       ranges::stable_partition(a,
         [&](ull x) { return b[i++] = (~x >> h) & 1; });
+      for (int i = 0; i < n; i++)
+        assert(b[i] == ((~a[i] >> h) & 1));
       bv[h] = b;
     }
   }