switch test

Author: lrvideckis

library/trees/linear_kth_path.hpp

@@ -1,7 +1,8 @@
 #define PROBLEM \
   "https://judge.yosupo.jp/problem/jump_on_tree"
 #include "../template.hpp"
-#include "../../../library/trees/linear_kth_path.hpp"
+#include "../../../library/trees/linear_lca.hpp"
+#include "../../../library/trees/ladder_decomposition/linear_kth_par.hpp"
 #include "../../../library/trees/lca_rmq/lca_rmq.hpp"
 #include "../compress_tree_asserts.hpp"
 int main() {
@@ -15,12 +16,19 @@ int main() {
     adj[u].push_back(v);
     adj[v].push_back(u);
   }
-  linear_kth_path lin_kth_path(adj);
+  linear_lca lin_lca(adj);
+  linear_kth_par lin_kth_par(adj);
   LCA lc(adj);
   compress_tree_asserts(adj, lc);
   while (q--) {
     int u, v, k;
     cin >> u >> v >> k;
-    cout << lin_kth_path.kth_path(u, v, k) << '\n';
+    int lca_d = lin_kth_par.t[lin_lca.lca(u, v)].d;
+    int u_lca = lin_kth_par.t[u].d - lca_d;
+    int v_lca = lin_kth_par.t[v].d - lca_d;
+    if (k <= u_lca) cout << lin_kth_par.kth_par(u, k) << '\n';
+    else if (k <= u_lca + v_lca)
+      cout << lin_kth_par.kth_par(v, u_lca + v_lca - k) << '\n';
+    else cout << -1 << '\n';
   }
 }