LibreOJ: 105

文艺平衡树

Author: Macesuted

LibreOJ/105.cpp

@@ -0,0 +1,99 @@
+/**
+ * @file 105.cpp
+ * @author Macesuted ([email protected])
+ * @date 2022-05-01
+ *
+ * @copyright Copyright (c) 2022
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+bool mem1;
+
+class FhqTreap {
+   private:
+    struct Node {
+        Node *l, *r;
+        int val, rnk, siz;
+        bool rev;
+        Node(int val_) { l = r = NULL, val = val_, rnk = rand(), siz = 1, rev = false; }
+    };
+
+    Node* root;
+
+    int getSiz(Node* p) { return p ? p->siz : 0; }
+    void rev(Node* p) { return p && (swap(p->l, p->r), p->rev ^= true), void(); }
+    void pushDown(Node* p) { return p && p->rev && (rev(p->l), rev(p->r), p->rev = false), void(); }
+    void pushUp(Node* p) { return p->siz = 1 + getSiz(p->l) + getSiz(p->r), void(); }
+    void split(Node* p, Node*& t1, Node*& t2, int s) {
+        if (!p) return t1 = t2 = NULL, void();
+        pushDown(p);
+        if (1 + getSiz(p->l) <= s)
+            t1 = p, split(p->r, t1->r, t2, s - 1 - getSiz(p->l));
+        else
+            t2 = p, split(p->l, t1, t2->l, s);
+        return pushUp(p);
+    }
+    void merge(Node*& p, Node* t1, Node* t2) {
+        if (!t1) return p = t2, void();
+        if (!t2) return p = t1, void();
+        if (t1->rnk < t2->rnk)
+            pushDown(p = t1), merge(p->r, t1->r, t2);
+        else
+            pushDown(p = t2), merge(p->l, t1, t2->l);
+        return pushUp(p);
+    }
+    void print(Node* p) {
+        if (!p) return;
+        pushDown(p);
+        print(p->l), cout << p->val << ' ', print(p->r);
+        return;
+    }
+
+   public:
+    FhqTreap(void) { root = NULL; }
+    void build(int n) {
+        for (int i = 1; i <= n; i++) merge(root, root, new Node(i));
+        return;
+    }
+    void reverse(int l, int r) {
+        Node *tc = NULL, *tr = NULL;
+        split(root, root, tr, r), split(root, root, tc, l - 1);
+        rev(tc);
+        merge(root, root, tc), merge(root, root, tr);
+        return;
+    }
+    void print(void) { return print(root), cout << endl, void(); }
+} FHQ;
+
+void solve(void) {
+    int n, m;
+    cin >> n >> m;
+    FHQ.build(n);
+    for (int i = 1; i <= m; i++) {
+        int l, r;
+        cin >> l >> r;
+        FHQ.reverse(l, r);
+    }
+    FHQ.print();
+    return;
+}
+
+bool mem2;
+
+int main() {
+    ios::sync_with_stdio(false);
+#ifdef LOCAL
+    cerr << "Memory Cost: " << abs(&mem1 - &mem2) / 1024. / 1024. << "MB" << endl;
+#endif
+
+    int _ = 1;
+    while (_--) solve();
+
+#ifdef LOCAL
+    cerr << "Time Cost: " << clock() * 1000. / CLOCKS_PER_SEC << "MS" << endl;
+#endif
+    return 0;
+}