【动态树】 HDOJ 5398 GCD Tree

LCT维护最大生成树。。。。。然而这种题目比赛的时候根本不敢写。。。

#include <bits/stdc++.h>using namespace std;#define mp(x, y) make_pair(x, y)const int maxn = 100005;const int maxm = 300005;const int INF = 0x3f3f3f3f * 2;struct node *null;struct node{int size, rev, t1, t2;       pair<int, node*> Min, cMin;node *fa, *ch[2];void init(){size = rev = 0;fa = ch[0] = ch[1] = null;}inline bool d(){return fa->ch[1] == this;}inline bool isroot(){return fa == null || fa->ch[0] != this && fa->ch[1] != this;}inline void setc(node *p, int d){ch[d] = p;p->fa = this;}inline void pushup(){size = ch[0]->size + ch[1]->size + 1;Min = cMin;if(ch[0] != null) Min = min(Min, ch[0]->Min);if(ch[1] != null) Min = min(Min, ch[1]->Min);}inline void flip(){if(this == null) return;swap(ch[0], ch[1]);rev ^= 1;}inline void pushdown(){if(rev) {ch[0]->flip();ch[1]->flip();rev = 0;}}inline void go(){if(!isroot()) fa->go();pushdown();}void rot(){node *f = fa, *ff = fa->fa;int c = d(), cc = fa->d();f->setc(ch[!c], c);this->setc(f, !c);if(ff->ch[cc] == f) ff->setc(this, cc);else this->fa = ff;f->pushup();}node* splay(){go();while(!isroot()) {if(!fa->isroot()) d() == fa->d() ? fa->rot() : rot();rot();}pushup();return this;}node* access(){for(node *p = this, *q = null; p != null; q = p, p = p->fa) {p->splay()->setc(q, 1);p->pushup();}return splay();}inline void makeroot(){access()->flip();}node* getroot() {node *x;for(x = access(); x->pushdown(), x->ch[0] != null; x = x->ch[0]);return x;}void cut(){access();ch[0]->fa = null;ch[0] = null;pushup();}void cut(node *o){makeroot();o->cut();}void link(node *p){makeroot();fa = p;}}*Node[maxn], pool[maxm], *tail;int res[maxn];vector<int> vec[maxn];int n;pair<int, node*> query(node *a, node *b){a->access();for(a = null; b != null; a = b, b = b->fa) {b->splay();if(b->fa == null) return min(b->ch[1]->Min, a->Min);b->setc(a, 1);b->pushup();}}node* newnode(){node *p = tail++;p->fa = p->ch[0] = p->ch[1] = null;p->size = p->rev = 0;p->Min = p->cMin = mp(INF, p);return p;}void init(){tail = pool;null = newnode();for(int i = 1; i <= n; i++) Node[i] = newnode();for(int i = n; i >= 1; i--) for(int j = i + i; j <= n; j += i)vec[j].push_back(i);int ans = 0;for(int i = 2; i <= n; i++) {int t = vec[i][0];node *p = newnode();p->t1 = i, p->t2 = t;p->cMin = p->Min = mp(t, p);p->link(Node[i]);p->link(Node[t]);ans += t;for(int j = 1; j < vec[i].size(); j++) {t = vec[i][j];pair<int, node*> tpair = query(Node[i], Node[t]);if(tpair.first >= t) continue;ans -= tpair.first;ans += t;p = tpair.second;int t1 = p->t1;int t2 = p->t2;p->cut(Node[t1]);p->cut(Node[t2]);p->init();p->t1 = i, p->t2 = t;p->Min = p->cMin = mp(t, p);p->link(Node[i]);p->link(Node[t]);}res[i] = ans;}}int main(){n = 100000;init();int t;while(scanf("%d", &t) != EOF) {printf("%d\n", res[t]);}return 0;}