another place

Author: lrvideckis

library/data_structures/seg_tree_uncommon/merge_sort_tree.hpp

@@ -2,15 +2,13 @@
 #include "../lazy_seg_tree_midpoint.hpp"
 struct merge_sort_tree {
   int n;
-  vector<vi> tree;
+  vector<basic_string<int>> tree;
   merge_sort_tree(const vi& a): n(sz(a)), tree(2 * n) {
     int pw2 = bit_ceil(size(a));
     rep(i, 0, n) tree[(i + pw2) % n + n] = {a[i]};
     for (int i = n - 1; i >= 1; i--) {
-      tree[i].resize(
-        sz(tree[2 * i]) + sz(tree[2 * i + 1]));
       ranges::merge(tree[2 * i], tree[2 * i + 1],
-        begin(tree[i]));
+        back_inserter(tree[i]));
     }
   }
   //! count of i in [l, r) such that a[i] in [vl, vr)