BZOJ1098 Office Building Biu (bfs+ list optimization)

Links: http://www.lydsy.com/JudgeOnline/problem.php?id=1098
Analysis: see note.

1 //complement graph connected block BFS + chain list optimization2#include <cstdio>3#include <queue>4#include <vector>5#include <algorithm>6 using namespacestd;7 8 structEdge {9     intto, NXT;Ten }; One  A structNode { -     intPre, NXT; - }; the  - Const intMAXM =2000000+5; - Const intMAXN =100000+5; -  + intN, M, CNT; - intHEAD[MAXN], VIS[MAXN], VI[MAXN]; +Edge E[MAXM <<1]; A Node L[MAXN]; atvector<int>ans; -  - voidAdd_edge (intUintv) { -E[++cnt].to = v; E[CNT].NXT = Head[u]; Head[u] =CNT; -e[++cnt].to = u; E[CNT].NXT = Head[v]; HEAD[V] =CNT; - } in  - voidDel_node (intp) { toL[L[P].PRE].NXT =l[p].nxt; +L[l[p].nxt].pre =L[p].pre; - } the  * voidBFs () { $queue<int> q;//maintain nodes to be expanded in the current fill graph connected blockPanax Notoginseng      while(l[0].nxt! =0) {//The current list is not empty, indicating that the node does not belong to any of the connected blocks -         intp = l[0].NXT;//enumerates a node that exists in a linked list and becomes the first node in a new connected block theDel_node (P);//Remove this node from the linked list +Q.push (P);//node Queue A         intsum =1;//current number of connected blocks is 1 the          while(!q.empty ()) {//continuously to the node in the current connected block to find the complement graph of the connected nodes are removed from the list and joined to the queue +p = Q.front (); Q.pop ();//eject a node in a connected block -              for(inti = head[p]; I i = e[i].nxt)//enumerates the edges of this node and marks $Vis[e[i].to] =1; $              for(inti = l[0].NXT; I i = l[i].nxt)//finds a node that is not currently part of any connected block, and if it is not marked, is a complement to the P node, the number of nodes of this connected block is increased and the Unicom node is added to the queue and removed from the list -                 if(!vis[i]) {sum++; Q.push (i); Del_node (i);} -              for(inti = head[p]; I i = e[i].nxt) vis[e[i].to] =0;//Recovery token, the flagged node may be a complement to the nodes in the current block (in the queue) that need to be expanded the         } -Ans.push_back (sum);//saves the number of nodes in the complete connected block in the arrayWuyi     } the } -  Wu intMain () { -scanf"%d%d", &n, &m); About      for(inti =1, u, v; I <= m; i++) {//Building Map $scanf"%d%d", &u, &v); - Add_edge (U, v); -     } -      for(inti =1; I <= N; i++) {//initializes the node 1 ~ N to a list (maintaining nodes that are not in any of the connected blocks), L[0].NXT points to the header node in the current list, and the list is empty if l[0].nxt = 0 AL[i].pre = i-1; +L[I].NXT = i +1; the} l[0].NXT =1; L[N].NXT =0; -BFS ();//A connecting block for the BFS $printf"%d\n", Ans.size ());//number of output connected blocks theSort (Ans.begin (), Ans.end ());//sort the number of connected blocks in ascending order the      for(inti =0; I < ans.size (); i++)//the number of connected blocks is output in ascending order theprintf"%d", Ans[i]); the     return 0; -}

BZOJ1098 Office Building Biu (bfs+ list optimization)