从ZOJ2114（Transportation Network）到Link-cut-tree（LCT）

  1 #include <cstdio>
  2 #include <cstring>
  3 #include <algorithm>
  4 
  5 enum { Left=0,Right=1 };
  6 
  7 struct SplayNode;
  8 SplayNode* vir;
  9 
 10 struct SplayNode
 11 {
 12     int dist;
 13     int totDist;
 14     bool isRoot;
 15     SplayNode* parent;
 16     SplayNode* child[2];
 17 
 18     void init()
 19     {
 20         dist=totDist=0;
 21         isRoot=true;
 22         parent=child[0]=child[1]=vir;
 23     }
 24 
 25     void update()
 26     {
 27         this->totDist =
 28                 child[Left]->totDist+child[Right]->totDist+this->dist;
 29     }
 30 
 31     void rotate(int dir)
 32     //If dir==Right then rotate clockwise, else rotate counter-clockwise
 33     {
 34         if(parent==parent->parent->child[Left])
 35             parent->parent->child[Left]=this;
 36         else if(parent==parent->parent->child[Right])
 37             parent->parent->child[Right]=this;
 38 
 39         parent->child[dir^1]=this->child[dir];
 40         child[dir]->parent=this->parent;
 41 
 42         child[dir]=parent;
 43         parent=parent->parent;
 44         child[dir]->parent=this;
 45     }
 46 
 47     void zigzig(int dir)
 48     {
 49         parent->rotate(dir);
 50         this->rotate(dir);
 51 
 52         child[dir]->child[dir]->update();
 53         child[dir]->update();
 54         this->update();
 55     }
 56 
 57     void zigzag(int dir) //dir depends on first rotation
 58     {
 59         rotate(dir);
 60         rotate(dir^1);
 61 
 62         child[Left]->update();
 63         child[Right]->update();
 64         this->update();
 65     }
 66 
 67     void zig(int dir)
 68     {
 69         rotate(dir);
 70         child[dir]->update();
 71         this->update();
 72     }
 73 
 74     void splay()
 75     {
 76         while(!isRoot)
 77         {
 78             int status=0;
 79             if(this==parent->child[Left]) status|=1;
 80             else status|=2;
 81 
 82             if(!parent->isRoot)
 83             {
 84                 if(parent->parent->isRoot) this->isRoot=true;
 85                 if(parent==parent->parent->child[Left]) status|=4;
 86                 else status|=8;
 87             }
 88             else
 89                 this->isRoot=true;
 90 
 91             switch(status)
 92             {
 93             case 1: zig(Right);
 94                     child[Right]->isRoot=false;
 95                     break;
 96             case 2: zig(Left);
 97                     child[Left]->isRoot=false;
 98                     break;
 99             case 5: zigzig(Right);
100                     if(isRoot) child[Right]->child[Right]->isRoot=false;
101                     break;
102             case 6: zigzag(Left);
103                     if(isRoot) child[Right]->isRoot=false;
104                     break;
105             case 9: zigzag(Right);
106                     if(isRoot) child[Left]->isRoot=false;
107                     break;
108             case 10:zigzig(Left);
109                     if(isRoot) child[Left]->child[Left]->isRoot=false;
110                     break;
111             default:break;
112             }
113         }
114     }
115 };
116 
117 int access(SplayNode* u)
118 {
119     SplayNode* v=vir;
120     int res=0;
121     while(u!=vir)
122     {
123         u->splay();
124         u->child[Right]->isRoot=true;
125         res=u->child[Right]->totDist;
126         u->child[Right]=v;
127         v->isRoot=false;
128         u->update();
129         v=u; u=u->parent;
130     }
131     return res + v->child[Right]->totDist;
132 }
133 
134 inline int query(SplayNode* u,SplayNode* v)
135 {
136     access(u);
137     return access(v);
138 }
139 
140 void initVir()
141 {
142     vir=new SplayNode;
143     vir->init();
144 }
145 
146 const int maxN=20005;
147 
148 SplayNode node[maxN];
149 int center[maxN];
150 int N,Q;
151 int lastRes=0;
152 
153 inline void link(int u,int v,int len)
154 {
155     access(node+u);
156     node[u].splay();
157     center[u]=v;
158     node[u].parent=node+v;
159     node[u].dist=len;
160     node[u].update();
161 }
162 
163 inline void initNode()
164 {
165     for(int i=1;i<=N;i++) node[i].init();
166     for(int i=1;i<=N;i++) center[i]=i;
167 }
168 
169 int getCenter(int x)
170 {
171     return center[x]==x ? x :
172            center[x]=getCenter(center[x]);
173 }
174 
175 #define DEBUG
176 #undef DEBUG
177 
178 #ifdef DEBUG
179 int qc=0;
180 #endif
181 
182 void solve()
183 {
184     lastRes=0;
185     scanf("%d%d",&N,&Q);
186     initNode();
187     char cmd;
188     int v1,v2,len;
189     while(Q--)
190     {
191         do cmd=getchar(); while(cmd==‘ ‘ || cmd==‘\n‘);
192         if(cmd==‘Q‘)
193         {
194             scanf("%d%d",&v1,&v2);
195             if(getCenter(v1)==getCenter(v2))
196                 printf("%d\n",lastRes=query(node+v1,node+v2));
197             else printf("Not connected.\n");
198 #ifdef DEBUG
199             printf("#%d query successful.\n",++qc);
200 #endif
201         }
202         else
203         {
204             scanf("%d%d%d",&v1,&v2,&len);
205 #ifndef DEBUG
206             v1=(v1-lastRes-1)%N;
207             if(v1<=0) v1+=N;
208             v2=(v2-lastRes-1)%N;
209             if(v2<=0) v2+=N;
210 #endif
211             link(getCenter(v1),getCenter(v2),len);
212         }
213     }
214 }
215 
216 int main()
217 {
218     initVir();
219     int X; scanf("%d",&X);
220     while(X--) solve();
221     return 0;
222 }