Rename query_impl to query for clarity

Author: lrvideckis

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

@@ -14,16 +14,16 @@ struct merge_sort_tree {
   //! @time O(log(n)^2)
   //! @space O(1)
   int query(int l, int r, int vl, int vr) {
-    return query_impl(l, r, vl, vr, 0, n, 1);
+    return query(l, r, vl, vr, 0, n, 1);
   }
-  int query_impl(int l, int r, int vl, int vr, int tl,
+  int query(int l, int r, int vl, int vr, int tl,
     int tr, int v) {
     if (r <= tl || tr <= l) return 0;
     if (l <= tl && tr <= r)
       return ranges::lower_bound(tree[v], vr) -
         ranges::lower_bound(tree[v], vl);
     int tm = split(tl, tr);
-    return query_impl(l, r, vl, vr, tl, tm, 2 * v) +
-      query_impl(l, r, vl, vr, tm, tr, 2 * v + 1);
+    return query(l, r, vl, vr, tl, tm, 2 * v) +
+      query(l, r, vl, vr, tm, tr, 2 * v + 1);
   }
 };