Ladder nit (#215)

* nits

* [auto-verifier] verify commit d131623

* reverting

---------

Co-authored-by: GitHub <noreply@github.com>

Author: lrvideckis

.verify-helper/timestamps.remote.json

@@ -141,7 +141,7 @@
 "tests/library_checker_aizu_tests/trees/hld_lib_checker_path.test.cpp": "2026-04-12 16:21:27 -0600",
 "tests/library_checker_aizu_tests/trees/hld_lib_checker_subtree_edges.test.cpp": "2026-04-12 16:21:27 -0600",
 "tests/library_checker_aizu_tests/trees/hld_lib_checker_subtree_nodes.test.cpp": "2026-04-12 16:21:27 -0600",
-"tests/library_checker_aizu_tests/trees/kth_path_ladder.test.cpp": "2026-04-25 22:43:50 -0600",
+"tests/library_checker_aizu_tests/trees/kth_path_ladder.test.cpp": "2026-04-26 11:11:53 -0600",
 "tests/library_checker_aizu_tests/trees/kth_path_linear.test.cpp": "2026-04-21 13:56:58 -0600",
 "tests/library_checker_aizu_tests/trees/kth_path_tree_lift.test.cpp": "2026-04-12 16:21:27 -0600",
 "tests/library_checker_aizu_tests/trees/lca_all_methods_aizu.test.cpp": "2026-04-21 13:56:58 -0600",

library/trees/uncommon/ladder_decomposition.hpp

@@ -14,41 +14,42 @@
 //! @endcode
 struct ladder {
   int n;
-  vi d, p, idx, l;
+  vi d, p, idx, lad;
   vector<vi> jmp;
   ladder(const auto& g):
-    n(sz(g)), d(n), p(n), idx(n), l(2 * n) {
+    n(sz(g)), d(n), p(n), idx(n), lad(2 * n) {
     int i = 0;
-    vi s(n);
+    vi st(n);
     auto dfs = [&](auto dfs, int u) -> vi {
       vi path;
-      s[d[u]] = u;
+      st[d[u]] = u;
       for (int v : g[u])
         if (v != p[u]) {
           d[v] = d[p[v] = u] + 1;
           vi x = dfs(dfs, v);
           if (sz(x) > sz(path)) swap(x, path);
           for (int y : x) idx[y] = i;
-          for (int y : x) l[i++] = y;
-          rep(j, 0, min(sz(x), d[v])) l[i++] = s[d[u] - j];
+          for (int y : x) lad[i++] = y;
+          rep(j, 0, min<int>(sz(x), d[v])) lad[i++] =
+            st[d[u] - j];
         }
       path.push_back(u);
       return path;
     };
     vi x = dfs(dfs, 0);
     for (int y : x) idx[y] = i;
-    for (int y : x) l[i++] = y;
+    for (int y : x) lad[i++] = y;
     jmp = treeJump(p);
   }
   int kth_par(int u, int k) {
     assert(0 <= k && k <= d[u]);
     if (k == 0) return u;
     int bit = __lg(k);
     u = jmp[bit][u], k -= (1 << bit);
-    int i = idx[u], j = i + d[l[i]] - d[u];
-    assert(l[j] == u);
-    // subarray [j, j+k] of l corresponds to the rest
+    int i = idx[u], j = i + d[lad[i]] - d[u];
+    assert(lad[j] == u);
+    // subarray [j, j+k] of lad corresponds to the rest
     // of the jump
-    return l[j + k];
+    return lad[j + k];
   }
 };

tests/library_checker_aizu_tests/trees/kth_path_ladder.test.cpp

@@ -1,8 +1,6 @@
 #define PROBLEM \
   "https://judge.yosupo.jp/problem/jump_on_tree"
 #include "../template.hpp"
-#undef sz
-#define sz(x) (int)ssize(x)
 #include "../../../library/trees/uncommon/ladder_decomposition.hpp"
 int main() {
   cin.tie(0)->sync_with_stdio(0);