【HDU4010】【LCT】Query on The Trees

  1 /*
  2 唐代白居易
  3 《浪淘沙·借问江潮与海水》
  4 借问江潮与海水，何似君情与妾心？
  5 相恨不如潮有信，相思始觉海非深。 
  6 */
  7 #include <iostream>
  8 #include <cstdio>
  9 #include <algorithm>
 10 #include <cstring>
 11 #include <vector>
 12 #include <utility>
 13 #include <iomanip>
 14 #include <string>
 15 #include <cmath>
 16 #include <queue>
 17 #include <assert.h>
 18 #include <map>
 19 #include <ctime>
 20 #include <cstdlib>
 21 #include <stack>
 22 #define LOCAL
 23 const int INF = 0x7fffffff;
 24 const int MAXN = 300000  + 10;
 25 const int maxnode = 1000000;
 26 const int maxm= 30000 * 2 + 10;
 27 using namespace std;
 28 
 29 struct Link_Cut_Tree{
 30        struct Node{//splay节点 
 31               int val, add;
 32               int Max, turn;
 33               Node *parent, *ch[2];
 34        }node[MAXN], *null;
 35        Node *pos;//计数
 36        Node *tmp[MAXN];
 37        
 38        void change(Node *u){access(u)->turn ^= 1;}//注意因为x是在右子树要翻转 
 39        void init(){
 40             //循环指针
 41             null = node;
 42             null->parent = null->ch[0] = null->ch[1] = null;
 43             null->Max = null->val = -INF;
 44             null->add = null->turn = 0;
 45             
 46             pos = node + 1;
 47        }
 48        //用这种方法实现快捷方便.便于直接查找 
 49        Node *NEW(int x){
 50             pos->Max = pos->val = x;
 51             pos->turn = pos->add = 0;
 52             pos->parent = pos->ch[0] = pos->ch[1] = null;
 53             return pos++;
 54        }
 55        //判断x是否是根，注意这个是判断是否是splay的根，而不是lct的根 
 56        bool is_root(Node *x){
 57             if (x == null || (x->parent->ch[0] != x && x->parent->ch[1] != x)) return 1;
 58             return 0;
 59        } 
 60        //标记下传 
 61        void pushdown(Node *x){
 62             if (x == null) return;
 63             if (x->turn){//翻转标记 
 64                
 65                if (x->ch[0] != null) x->ch[0]->turn ^= 1;
 66                if (x->ch[1] != null) x->ch[1]->turn ^= 1;
 67                swap(x->ch[0], x->ch[1]);//交换左右子树. 
 68                x->turn = 0;
 69             }
 70             //权值标记 
 71             if (x->add){
 72                if (x->ch[0] != null){
 73                   x->ch[0]->val += x->add;
 74                   x->ch[0]->Max += x->add;
 75                   x->ch[0]->add += x->add; 
 76                }
 77                if (x->ch[1] != null){
 78                   x->ch[1]->val += x->add;
 79                   x->ch[1]->Max += x->add;
 80                   x->ch[1]->add += x->add; 
 81                }
 82                x->add = 0;
 83             }
 84             return;
 85        }
 86        //更新 
 87        void update(Node *x){
 88             if (x == null) return;
 89             x->Max = max(x->val, max(x->ch[0]->Max, x->ch[1]->Max));
 90        }
 91       
 92        //d = 0为左旋,否则为右旋 
 93        void rotate(Node *x, int d){
 94             if (is_root(x)) return;//是根就不转
 95             Node *y = x->parent;
 96             y->ch[d ^ 1] = x->ch[d];
 97             if (x->ch[d] != null) x->ch[d]->parent = y; 
 98             x->parent = y->parent;
 99             if (y != null){
100                if (y == y->parent->ch[1]) y->parent->ch[1] = x;
101                else if (y == y->parent->ch[0]) y->parent->ch[0] = x;  
102             }
103             x->ch[d] = y;
104             y->parent = x;
105             update(y);
106        }
107        //将x转到根 
108        void splay(Node *x){
109             //带标记splay的伸展操作 
110             //将从顶部到根部的节点全部pushdown 
111             int cnt = 1;
112             tmp[0] = x;
113             for (Node *y = x; !is_root(y); y = y->parent) tmp[cnt++] = y->parent;
114             while (cnt) pushdown(tmp[--cnt]);
115             
116             while (!is_root(x)){
117                   Node *y = x->parent;
118                   if (is_root(y)) rotate(x, (x == y->ch[0]));
119                   else {
120                        int d = (y->parent->ch[0] == y);
121                        if (y->ch[d] == x) rotate(x, d ^ 1);
122                        else rotate(y, d);
123                        rotate(x, d);
124                   }
125             }
126             update(x);
127        }
128        //lct的访问操作,也是核心代码 
129        Node *access(Node *u){
130             Node *v = null;
131             while (u != null){//非lct根，总是放在右边 
132                   splay(u);
133                   v->parent = u;
134                   u->ch[1] = v;
135                   update(u);
136                   v = u;
137                   u = u->parent;
138             }
139             return v; 
140        }
141        //合并操作 
142        void merge(Node *u, Node *v){
143             //if (u->val == 2 && v->val == 5)
144             //printf("%d\n", u->ch[0]->val);
145             //注意u为根
146             access(u);
147             splay(u);
148             
149             u->turn = 1;//翻转,因为在access之后，u已经成为splay中深度最大的点，因此右子树为null，此时要成为根就要翻转 
150             u->parent = v; 
151        } 
152        void cut(Node *u){
153             access(u);
154             splay(u);
155             //注意到u为根，自然深度最小,分离出来 
156             u->ch[0]->parent = null;
157             u->ch[0] = null;
158             update(u); 
159        }
160        //找根,不是真根 
161        Node *findroot(Node *u){
162             access(u);//不仅要打通，而且要让u成为根 
163             splay(u);
164             
165             while (u->parent != null) u = u->parent;
166             return u;
167        }
168        //判断u和v是否在同一个子树中 
169        bool check(Node *u, Node *v){
170             while (u->parent != null) u = u->parent;
171             while (v->parent != null) v = v->parent;
172             return (u == v);
173        }
174 }splay;
175 int u[MAXN],v[MAXN];
176 int n, m;
177 /*struct Node{
178        Node *ch[2];
179        int val;
180 };
181 Node* rotate(Node *t, int d){
182      Node *p = t->ch[d ^ 1];
183      t->ch[d ^ 1] = p->ch[d];
184      p->ch[d] = t;
185      t =  p;
186      return t; 
187 }*/
188 void init(){ 
189      splay.init();
190      for (int i = 1; i < n; i++) scanf("%d%d", &u[i], &v[i]);
191      //各点权值 
192      for (int i = 1; i <= n; i++){
193          int t;
194          scanf("%d", &t);
195          splay.NEW(t);
196      }
197      for (int i = 1; i < n; i++) {
198         // if (i == 3)
199         // printf("");
200          splay.merge(splay.node + u[i], splay.node + v[i]);
201          //printf("%d\n", splay.node[2].ch[0]->val);
202      }
203      //printf("%d", splay.check(splay.node + 4, splay.node + 5)); 
204 }
205 void work(){
206      scanf("%d", &m);
207      for (int i = 1; i <= m; i++){
208          int t;
209          scanf("%d", &t);
210          if (t == 1){//连接两点 
211             int u, v;
212             scanf("%d%d", &u, &v);
213             //判断是否在同一个lct树内 
214             if (splay.check(splay.node + u, splay.node + v)){
215                //printf("%d ", i);
216                printf("-1\n");
217                continue;
218             }
219             splay.merge(splay.node + u, splay.node + v);
220          }else if (t == 2){
221             int u, v;
222             scanf("%d%d", &u, &v);
223             //分离两颗树 
224             if (u == v || !splay.check(splay.node + u, splay.node + v)){
225                //printf("%d ", i);
226                printf("-1\n");
227                continue;
228             } 
229             //转根再分离 
230             splay.change(splay.node + u);//注意这个根是原树的根不是lct的根 
231             splay.cut(splay.node + v);
232          }else if (t == 3){
233                int u, v, w;
234                scanf("%d%d%d", &w, &u, &v);
235                //不再同一个树内自然无法更新 
236                if (!splay.check(splay.node + u, splay.node + v)){
237                   //printf("%d ", i);
238                   printf("-1\n");
239                   continue;
240                }
241                splay.change(splay.node + u);
242                splay.access(splay.node + v);
243                //将u换为真根，则u所在的splay都是v-u路径上的节点 
244                Link_Cut_Tree::Node *q = splay.findroot(splay.node + v);
245                q->add += w;
246                q->Max += w;
247                q->val += w;
248          }else {//查询操作 
249                int u, v;
250                scanf("%d%d", &u, &v);
251                if (!splay.check(splay.node + u, splay.node + v)){
252                   //printf("%d ", i);
253                   printf("-1\n");
254                   continue;
255                } 
256                //先换根 
257                splay.change(splay.node + u);
258                splay.access(splay.node + v);
259                printf("%d\n", splay.findroot(splay.node + v)->Max);
260          }
261      }
262      printf("\n");
263 }
264 
265 int main (){
266    
267     //scanf("%d", &n);
268     while (scanf("%d", &n) != EOF){
269           init();
270           work();
271     }
272     return 0;
273 }