node_partition.h
资源名称:leda.tar.gz [点击查看]
上传用户:gzelex
上传日期:2007-01-07
资源大小:707k
文件大小:2k
源码类别:
数值算法/人工智能
开发平台:
MultiPlatform
- /*******************************************************************************
- +
- + LEDA-R 3.2.3
- +
- + node_partition.h
- +
- + Copyright (c) 1995 by Max-Planck-Institut fuer Informatik
- + Im Stadtwald, 66123 Saarbruecken, Germany
- + All rights reserved.
- +
- *******************************************************************************/
- #ifndef LEDA_NODE_PARTITION_H
- #define LEDA_NODE_PARTITION_H
- //------------------------------------------------------------------------------
- // node partitions
- //------------------------------------------------------------------------------
- #include <LEDA/graph.h>
- /*{Manpage {node_partition} {} {Node Partitions}}*/
- #include <LEDA/partition.h>
- class node_partition : private partition
- {
- /*{Mdefinition
- An instance $P$ of the data type $node_partition$ is a partition of the nodes
- of a graph $G$.}*/
- public:
- void init(const graph& G);
- /*{Mcreation P }*/
- node_partition(const graph& G) { init(G); }
- /*{Mcreate creates a name var containing for every node $v$ in $G$ a
- block ${v}$.}*/
- ~node_partition() {}
- /*{Moperations 1.2 4.5}*/
- int same_block(node v, node w)
- { return partition::same_block(partition_item(v->data[2]),
- partition_item(w->data[2])); }
- /*{Mopl returns true if $v$ and $w$ belong to the
- same block of var, false otherwise.}*/
- void union_blocks(node v, node w)
- { partition::union_blocks(partition_item(v->data[2]),
- partition_item(w->data[2])); }
- /*{Mopl unites the blocks of var containing nodes
- $v$ and $w$.}*/
- void make_rep(node v)
- { partition::set_inf(partition_item(v->data[2]),v); }
- node find(node v)
- { return node(partition::inf(partition::find(partition_item(v->data[2])))); }
- /*{Mop returns a canonical representative node of
- the block that contains node $v$.}*/
- node operator()(node v) { return find(v); }
- /*{Mfunop returns var.find($v$). }*/
- };
- /*{Mimplementation
- A node partition for a graph $G$ is implemented by a combination of a
- partition $P$ and a node array of $partition_item$ associating with
- each node in $G$ a partition item in $P$. Initialization takes linear time,
- union_blocks takes time $O(1)$ (worst-case), and same_block and find take
- time $O(alpha(n))$ (amortized). The space requirement is $O(n)$, where $n$
- is the number of nodes of $G$.}*/
- #endif