72 lines
1.7 KiB
Go
72 lines
1.7 KiB
Go
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// CookieJar - A contestant's algorithm toolbox
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// Copyright 2013 Peter Szilagyi. All rights reserved.
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//
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// CookieJar is dual licensed: use of this source code is governed by a BSD
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// license that can be found in the LICENSE file. Alternatively, the CookieJar
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// toolbox may be used in accordance with the terms and conditions contained
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// in a signed written agreement between you and the author(s).
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// Package graph implements a simple graph data structure and supporting API to
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// allow implementing graph alogirthms on top.
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package graph
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import (
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"gopkg.in/karalabe/cookiejar.v2/collections/bag"
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)
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// Data structure for representing a graph.
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type Graph struct {
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nodes int
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infos map[int]interface{}
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edges []*bag.Bag
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}
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// Creates a new undirected graph.
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func New(vertices int) *Graph {
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g := &Graph{
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nodes: vertices,
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infos: make(map[int]interface{}),
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edges: make([]*bag.Bag, vertices),
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}
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for i := 0; i < vertices; i++ {
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g.edges[i] = bag.New()
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}
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return g
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}
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// Returns the number of vertices in the graph.
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func (g *Graph) Vertices() int {
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return g.nodes
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}
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// Assigns some data to a graph node.
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func (g *Graph) Assign(id int, data interface{}) {
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g.infos[id] = data
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}
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// Retrieves the data associated with a graph node.
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func (g *Graph) Retrieve(id int) interface{} {
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return g.infos[id]
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}
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// Connects two vertices of a graph (may be a loopback).
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func (g *Graph) Connect(a, b int) {
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g.edges[a].Insert(b)
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if a != b {
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g.edges[b].Insert(a)
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}
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}
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// Disconnects two vertices of a graph (may be a loopback).
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func (g *Graph) Disconnect(a, b int) {
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g.edges[a].Remove(b)
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if a != b {
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g.edges[b].Remove(a)
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}
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}
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// Executes a function for every neighbor of a vertex.
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func (g *Graph) Do(v int, f func(interface{})) {
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g.edges[v].Do(f)
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}
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