speedup one test

Author: lrvideckis

library/data_structures/seg_tree_uncommon/merge_sort_tree.hpp

@@ -13,20 +13,20 @@ struct merge_sort_tree {
         begin(tree[i]));
     }
   }
-  //! count of i in [l, r) such that a[i] in [vl, vr)
+  //! count of i in [l, r) such that a[i] < x
   //! @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);
+  int query(int l, int r, int x) {
+    return query_impl(l, r, x, 0, n, 1);
   }
-  int query_impl(int l, int r, int vl, int vr, int tl,
-    int tr, int v) {
+  int query_impl(int l, int r, int x, 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);
+      return ranges::lower_bound(tree[v], x) -
+        begin(tree[v]);
     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_impl(l, r, x, tl, tm, 2 * v) +
+      query_impl(l, r, x, tm, tr, 2 * v + 1);
   }
 };

tests/library_checker_aizu_tests/strings/lcs_queries_merge_sort_tree.test.cpp

@@ -1,5 +1,7 @@
 #define PROBLEM \
   "https://judge.yosupo.jp/problem/prefix_substring_lcs"
+// as debug mode causes lower_bound (in MST) to be O(n)
+#undef _GLIBCXX_DEBUG
 #include "../template.hpp"
 #include "../../../library/strings/longest_common_subsequence/lcs_dp.hpp"
 #include "../../../library/data_structures/seg_tree_uncommon/merge_sort_tree.hpp"
@@ -30,7 +32,7 @@ int main() {
   for (int i = 0; i < q; i++) {
     int a, b, c;
     cin >> a >> b >> c;
-    cout << msts[a].query(b, c, -1, b) << '\n';
+    cout << msts[a].query(b, c, b) << '\n';
   }
   return 0;
 }

tests/library_checker_aizu_tests/strings/lcs_queries_wavelet.test.cpp

@@ -0,0 +1,36 @@
+#define PROBLEM \
+  "https://judge.yosupo.jp/problem/prefix_substring_lcs"
+#include "../template.hpp"
+#include "../../../library/strings/longest_common_subsequence/lcs_dp.hpp"
+#include "../../../library/data_structures/seg_tree_uncommon/wavelet_matrix.hpp"
+int main() {
+  cin.tie(0)->sync_with_stdio(0);
+  int q;
+  string s, t;
+  cin >> q >> s >> t;
+  vector<wavelet_matrix> msts;
+  {
+    lcs_dp lcs(t);
+    msts.emplace_back(vector<ull>(all(lcs.dp)));
+    for (char c : s) {
+      lcs.push_onto_s(c);
+      {
+        vector<bool> seen(sz(t));
+        for (int i = 0; i < sz(t); i++) {
+          int val = lcs.dp[i];
+          assert(val <= i);
+          if (val == -1) continue;
+          assert(!seen[val]);
+          seen[val] = 1;
+        }
+      }
+      msts.emplace_back(vector<ull>(all(lcs.dp)));
+    }
+  }
+  for (int i = 0; i < q; i++) {
+    int a, b, c;
+    cin >> a >> b >> c;
+    cout << msts[a].count(b, c, b) << '\n';
+  }
+  return 0;
+}