Create 14131_Okret.cpp

조서현/14131_Okret.cpp

@@ -0,0 +1,156 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+struct node
+{
+    node *l, *r, *p;
+    int cnt; 
+    char v;
+    bool flip, dummy;
+
+    node(char v, node* p) : l(nullptr), r(nullptr), p(p), cnt(1), v(v) {}
+    node(char v) : node(v, nullptr) {}
+    node() : node(0) {}
+
+    ~node() {
+        // if (l) delete l;
+        // if (r) delete r;
+    }
+} *tree, *nodes[2500010];
+
+char arr[2500010];
+
+void update(node* x){
+    x->cnt = 1;
+    if (x->l) {
+        x->cnt += x->l->cnt;
+    }
+    if (x->r) {
+        x->cnt += x->r->cnt;
+    }
+}
+
+void propagate(node* x){
+    if (!x->flip) return;
+    swap(x->l, x->r);
+    if (x->l) x->l->flip = !x->l->flip;
+    if (x->r) x->r->flip = !x->r->flip;
+    x->flip = false;
+}
+
+void rotate(node* x){
+    node* p = x->p;
+    node* b = nullptr;
+    if (!p) return; // x가 루트라면 종료
+    propagate(p); propagate(x);
+    if (x == p->l) { // x가 왼쪽 자식
+        p->l = b = x->r;
+        x->r = p;
+    } else { // x가 오른쪽 자식
+        p->r = b = x->l;
+        x->l = p;
+    } // x가 p의 부모가 됨
+    x->p = p->p;
+    p->p = x;
+    if (b) b->p = p;
+    (x->p ? (p==x->p->l ? x->p->l : x->p->r) : tree) = x;
+    update(p); update(x);
+}
+
+void splay(node* x){
+    while (x->p){ // x가 루트가 될 때까지
+        node* p = x->p;
+        node* g = p->p; // x의 조상의 조상
+        if (g){
+            // g의 왼쪽 왼쪽이 or 오른쪽 오른쪽이 x일 경우
+            if ((x==p->l) == (p==g->l)) rotate(p);
+            else rotate(x);
+        }
+        rotate(x);
+    }
+}
+
+void findKth(int k){
+    node* x = tree;
+    propagate(x);
+    while (true){
+        while (x->l && x->l->cnt > k){
+            x = x->l; propagate(x);
+        }
+        if (x->l) k -= x->l->cnt;
+        if (!k--) break;
+        x = x->r;
+        propagate(x);
+    }
+    splay(x);
+}
+
+void initTree(int n){
+    tree = new node(numeric_limits<char>::min()); tree->dummy = true; // left dummy
+    auto cur = tree;
+    for (int i = 1; i <= n; i++){
+        nodes[i] = cur->r = new node(arr[i-1], cur);
+        cur = cur->r;
+    }
+    cur->r = new node(numeric_limits<char>::max(), cur); cur->r->dummy = true; // right dummy
+    for (int i = n + 1; i >= 0; i--){
+        if (nodes[i])
+            update(nodes[i]);
+    }
+    if (n == 1) return;
+    splay(nodes[n >> 1]);
+}
+
+void interval(int s, int e){
+    findKth(s - 1);
+    node* x = tree;
+    tree = x->r;
+    tree->p = nullptr; // 일시적으로 연결을 끊고
+    findKth(e - s + 1);
+    x->r = tree;
+    tree->p = x; // 다시 연결
+    tree = x;
+}
+
+void flip(int s, int e){
+    interval(s, e);
+    auto cur = tree->r->l;
+    cur->flip = !cur->flip;
+}
+
+void print(node* cur){
+    if (cur == nullptr) return;
+    propagate(cur);
+    print(cur->l);
+    if (!cur->dummy) cout << cur->v;
+    print(cur->r);
+}
+
+// for splay tree study
+void prefix(node* cur, int level=0, string str="ROOT:"){
+    if (cur == nullptr) return;
+    for (int i = 0; i < level; i++) cout << "  ";
+    cout << str << " (" << cur->v << " " << cur->cnt << ")\n";
+    prefix(cur->l, level + 1, "L--");
+    prefix(cur->r, level + 1, "R--"); 
+}
+
+int main(){
+    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
+
+    // freopen("testcase.txt", "r", stdin);
+    // freopen("out1.txt", "w", stdout);
+
+    cin >> arr;
+    int n = strlen(arr), q; cin >> q;
+    initTree(n);
+
+    for (int i = 0; i < q; i++)
+    {
+        int a, b; cin >> a >> b;
+        flip(a, b);
+        // update(tree);
+    }
+    print(tree); cout << '\n';
+}