伸展树(splay)模板

神级数据结构

#include <iostream>#include <cstdio>#include <cmath>#include <algorithm>using namespace std;const int maxn = 200 + 7;int m, n;struct node {    node *left, *right;    node *par;    int val, w;} *root;void RightRotate(node *x) {    node *y = x->par;    y->left = x->right;    if(x->right) x->right->par = y;    x->par = y->par;    if(y->par) {        if(y->par->left == y) y->par->left = x;        else y->par->right = x;    }    x->right = y;    y->par = x;}void LeftRotate(node *x) {    node *y = x->par;    y->right = x->left;    if(x->left) x->left->par = y;    x->par = y->par;    if(y->par) {        if(y->par->left == y) y->par->left = x;        else y->par->right = x;    }    x->left = y;    y->par = x;}void splay(node *x, node *y) {    while(x->par != y) {        if(x->par->par == y) x->par->left == x ? RightRotate(x) : LeftRotate(x);        else {            if(x->par->par->left == x->par) {                if(x->par->left == x) {                    RightRotate(x);                    RightRotate(x);                } else {                    LeftRotate(x);                    RightRotate(x);                }            } else {                if(x->par->left == x) {                    RightRotate(x);                    LeftRotate(x);                } else {                    LeftRotate(x);                    LeftRotate(x);                }            }        }    }    if(y == 0) root = x;}void Insert(int val) {    node *p = root, *y = NULL;    int isL = 1;    while(true) {        if(!p) {            p = new node;            p->left = p->right = NULL;            p->val = val;            p->w = 1;            p->par = y;            if(y) {                if(isL) y->left = p;                else y->right = p;            }            splay(p, 0);            break;        }        y = p;        if(p->val == val) {            p->w++;            splay(p, 0);            break;        } else if(p->val < val) {            p = p->right;            isL = 0;        } else {            p = p->left;            isL = 1;        }    }}node *join(node *a, node *b) {    if(!a) return b;    if(!b) return a;    a->par = b->par = 0;    node *t = a;    while(t->right) t = t->right;    splay(t, 0);    t->right = b;    b->par = t;    return t;}void Remove(node *x, int val) {    if(x->val == val) {        splay(x, 0);        root = join(x->left, x->right);        return ;    } else if(x->val > val) {        Remove(x->left, val);    } else Remove(x->right, val);}void print(node *d) {    if(d->left) print(d->left);    if(d->right) print(d->right);    printf("%d  ", d->val);}int main() {    //freopen("in.txt", "r", stdin);    //freopen("out.txt", "w", stdout);    scanf("%d", &n);    int x;    for(int i = 0; i < n; ++i) {        scanf("%d", &x);        Insert(x);        print(root); printf("\n");    }    scanf("%d", &m);    for(int i = 0; i < m; ++i) {        scanf("%d", &x);        Remove(root, x);        print(root); printf("\n");    }    return 0;}