P8511 [Ynoi Easy Round 2021] TEST_68

https://www.luogu.com.cn/record/101246432

Luogu/P8511/P8511.cpp

@@ -0,0 +1,135 @@
+#include <iostream>
+#include <algorithm>
+#include <cstring>
+#include <functional>
+#include <unordered_map>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 5e5 + 5;
+
+int n, fa[N];
+long long a[N], max, ans[N];
+std::vector<int> g[N];
+std::unordered_map<long long, int> lst;
+bool vis[N];
+int cnt = 1, tr[N * 60][2];
+
+void insert(long long x) {
+    int p = 1;
+
+    for (int i = 60; i >= 0; i--) {
+        bool ch = (x >> i) & 1;
+
+        if (!tr[p][ch]) {
+            tr[p][ch] = ++cnt;
+        }
+
+        p = tr[p][ch];
+    }
+}
+
+long long query(long long x) {
+    int p = 1;
+    long long res = 0;
+
+    for (int i = 60; i >= 0; i--) {
+        int ch = (x >> i) & 1;
+
+        if (!p) break;
+
+        if (tr[p][ch ^ 1]) {
+            res |= 1ll << i;
+            p = tr[p][ch ^ 1];
+        } else {
+            p = tr[p][ch];
+        }
+    }
+
+    return res;
+}
+
+void solve(int x) {
+    max = 0;
+    cnt = 1;
+    memset(tr, 0x00, sizeof(tr));
+    std::vector<int> vec;
+    std::vector<bool> vis2(n + 1);
+
+    for (int i = x; i; i = fa[i]) {
+        vec.emplace_back(i);
+        vis[i] = true;
+        vis2[i] = true;
+    }
+
+    std::reverse(vec.begin(), vec.end());
+
+    std::function<void(int)> get = [&](int u) -> void {
+        insert(a[u]);
+        max = std::max(max, query(a[u]));
+
+        for (int v : g[u]) {
+            get(v);
+        }
+    };
+
+    for (int u : vec) {
+        ans[u] = max;
+
+        for (int v : g[u]) {
+            if (vis2[v]) continue;
+
+            get(v);
+        }
+
+        insert(a[u]);
+        max = std::max(max, query(a[u]));
+    }
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n;
+
+    for (int i = 2; i <= n; i++) {
+        cin >> fa[i];
+
+        g[fa[i]].emplace_back(i);
+    }
+
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+    }
+
+    for (int i = 1; i <= n; i++) {
+        max = std::max(max, query(a[i]));
+        insert(a[i]);
+    }
+
+    int x = 1, y = 1;
+
+    for (int i = 1; i <= n; i++) {
+        lst[a[i]] = i;
+
+        if (lst.count(a[i] ^ max)) {
+            x = i;
+            y = lst[a[i] ^ max];
+
+            break;
+        }
+    }
+
+    solve(x);
+    solve(y);
+
+    for (int i = 1; i <= n; i++) {
+        cout << (vis[i] ? ans[i] : max) << endl;
+    }
+
+    return 0;
+}