P2596 [ZJOI2006]书架

https://www.luogu.com.cn/record/79350717

Luogu/P2596/P2596.cpp

@@ -0,0 +1,215 @@
+#include <iostream>
+#include <cstdlib>
+#include <string>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 8e4 + 5;
+
+struct node {
+    node *lchild, *rchild, *fa;
+    std::size_t size;
+    int value, key;
+
+    node()
+        : lchild(nullptr), rchild(nullptr), fa(nullptr), size(0), value(0), key(rand()) {}
+
+    node(int _value)
+        : lchild(nullptr), rchild(nullptr), fa(nullptr), size(1), value(_value), key(rand()) {}
+
+    ~node() {
+        if (lchild != nullptr) delete lchild;
+        if (rchild != nullptr) delete rchild;
+    }
+
+    inline std::size_t lsize() {
+        return lchild == nullptr ? 0 : lchild->size;
+    }
+
+    inline std::size_t rsize() {
+        return rchild == nullptr ? 0 : rchild->size;
+    }
+
+    inline void pushup() {
+        size = 1;
+
+        if (lchild != nullptr) {
+            size += lchild->size;
+            lchild->fa = this;
+        }
+
+        if (rchild != nullptr) {
+            size += rchild->size;
+            rchild->fa = this;
+        }
+    }
+
+    inline std::size_t pos() {
+        std::size_t ret = lsize() + 1;
+        node *cur = this;
+
+        while (cur->fa != nullptr) {
+            if (cur->fa->rchild == cur) {
+                ret += cur->fa->lsize() + 1;
+            }
+
+            cur = cur->fa;
+        }
+
+        return ret;
+    }
+};
+
+int n, m;
+node *root, *p[N];
+
+std::pair<node *, node *> split(node *u, int k) {
+    if (u == nullptr) return std::make_pair(nullptr, nullptr);
+
+    if (k <= u->lsize()) {
+        auto o = split(u->lchild, k);
+
+        u->lchild = o.second;
+        u->pushup();
+        o.second = u;
+
+        return o;
+    }
+
+    auto o = split(u->rchild, k - u->lsize() - 1);
+
+    u->rchild = o.first;
+    u->pushup();
+    o.first = u;
+
+    return o;
+}
+
+template <typename... Args>
+node *merge(node *x, Args... args) {
+    return merge(x, merge(args...));
+}
+
+template <>
+node *merge(node *x, node *y) {
+    if (x == nullptr) return y;
+    if (y == nullptr) return x;
+
+    if (x->key < y->key) {
+        x->rchild = merge(x->rchild, y);
+        x->pushup();
+
+        return x;
+    }
+
+    y->lchild = merge(x, y->lchild);
+    y->pushup();
+
+    return y;
+}
+
+inline void top(const int &x) {
+    int k = p[x]->pos();
+
+    auto p = split(root, k - 1);
+    auto q = split(p.second, 1);
+
+    root = merge(q.first, p.first, q.second);
+}
+
+inline void bottom(const int &x) {
+    int k = p[x]->pos();
+
+    auto p = split(root, k - 1);
+    auto q = split(p.second, 1);
+
+    root = merge(p.first, q.second, q.first);
+}
+
+inline void insert(const int &x, const int &y) {
+    if (!y) return;
+
+    int k = p[x]->pos();
+    auto p = split(root, k - 1);
+    auto q = split(p.second, 1);
+
+    if (y > 0) {
+        auto t = split(q.second, y);
+        root = merge(p.first, t.first, q.first, t.second);
+    } else {  // y < 0
+        auto t = split(p.first, k + y - 1);
+        root = merge(t.first, q.first, t.second, q.second);
+    }
+}
+
+inline int ask(const int &x) {
+    return p[x]->pos() - 1;
+}
+
+inline int query(const int &x) {
+    auto p = split(root, x - 1);
+    auto q = split(p.second, 1);
+
+    int res = q.first->value;
+
+    root = merge(p.first, q.first, q.second);
+
+    return res;
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> m;
+
+    for (int i = 1, x; i <= n; i++) {
+        cin >> x;
+
+        root = merge(root, p[x] = new node(x));
+    }
+
+    while (m--) {
+        std::string op;
+        int s, t;
+
+        cin >> op >> s;
+
+        switch (op[0]) {
+            case 'T': {  // op == "Top"
+                top(s);
+
+                break;
+            }
+            case 'B': {  // op == "Bottom"
+                bottom(s);
+
+                break;
+            }
+            case 'I': {  // op == "Insert"
+                cin >> t;
+
+                insert(s, t);
+
+                break;
+            }
+            case 'A': {  // op == "Ask"
+                cout << ask(s) << endl;
+
+                break;
+            }
+            case 'Q': {  // op == "Query"
+                cout << query(s) << endl;
+
+                break;
+            }
+        }
+    }
+
+    // Cleanup
+    delete root;
+
+    return 0;
+}