圖(graph)
實現鄰接表
實際圖
graph.js
var Graph = function() {
//儲存頂點
var vertices = []
//邊
var adjList = {}
//新增頂點
this.addVertices = function(v) {
vertices.push(v)
adjList[v] = []
}
// 新增邊
this.addEdge = function(a, b) {
adjList[a].push(b)
adjList[b].push(a)
}
this.print = function() {
var s = '\n';
for (var i = 0; i < vertices.length; i++) {
var dingdian = vertices[i]
s += dingdian + '=>'
var bian = adjList[dingdian]
for (var j = 0; j < bian.length; j++) {
s += bian[j]
}
s += '\n'
}
console.log(s)
}
}
var g = new Graph()
g.addVertices('A')
g.addVertices('B')
g.addVertices('C')
g.addVertices('D')
g.addVertices('E')
g.addVertices('F')
g.addEdge('A', 'B')
g.addEdge('A', 'C')
g.addEdge('A', 'D')
g.addEdge('B', 'E')
g.addEdge('B', 'F')
g.addEdge('C', 'D')
g.print()
複製程式碼例項化
廣度優先
var Queue = function() {
var items = [];
//入隊
this.enqueue = function(el) {
items.push(el)
}
//出隊
this.dequeue = function() {
return items.shift();
}
// 隊頭
this.front = function() {
return items[0]
}
//隊是否為空
this.isEmpty = function() {
return items.length === 0;
}
//隊的長度
this.size = function() {
return items.length;
}
}
var Graph = function() {
//儲存頂點
var vertices = []
//邊
var adjList = {}
//新增頂點
this.addVertices = function(v) {
vertices.push(v)
adjList[v] = []
}
// 新增邊
this.addEdge = function(a, b) {
adjList[a].push(b)
adjList[b].push(a)
}
//white 未發現
//gray 已發現未探索
//black 已探索
var initColor = function() {
var color = {}
for (var i = 0; i < vertices.length; i++) {
color[vertices[i]] = 'white'
}
return color
}
this.bfs = function(v, callback) {
var color = initColor()
var queue = new Queue()
queue.enqueue(v)
while (!queue.isEmpty()) {
var now = queue.dequeue()
var bian = adjList[now]
for (var i = 0; i < bian.length; i++) {
var w = bian[i]
if (color[w] === 'white') {
color[w] = 'gray'
queue.enqueue(w)
}
}
color[now] = 'black'
if (callback) {
callback(now)
}
}
}
}
var g = new Graph()
g.addVertices('A')
g.addVertices('B')
g.addVertices('C')
g.addVertices('D')
g.addVertices('E')
g.addVertices('F')
g.addEdge('A', 'B')
g.addEdge('A', 'C')
g.addEdge('A', 'D')
g.addEdge('B', 'E')
g.addEdge('B', 'F')
g.addEdge('C', 'D')
複製程式碼例項化
最短路徑: 廣度優先
記錄，回溯路徑
var Queue = function() {
var items = [];
//入隊
this.enqueue = function(el) {
items.push(el)
}
//出隊
this.dequeue = function() {
return items.shift();
}
// 隊頭
this.front = function() {
return items[0]
}
//隊是否為空
this.isEmpty = function() {
return items.length === 0;
}
//隊的長度
this.size = function() {
return items.length;
}
}
var Graph = function() {
//儲存頂點
var vertices = []
//邊
var adjList = {}
//新增頂點
this.addVertices = function(v) {
vertices.push(v)
adjList[v] = []
}
// 新增邊
this.addEdge = function(a, b) {
adjList[a].push(b)
adjList[b].push(a)
}
this.print = function() {
var s = '\n';
for (var i = 0; i < vertices.length; i++) {
var dingdian = vertices[i]
s += dingdian + '=>'
var bian = adjList[dingdian]
for (var j = 0; j < bian.length; j++) {
s += bian[j]
}
s += '\n'
}
console.log(s)
}
//white 未發現
//gray 已發現未探索
//black 已探索
var initColor = function() {
var color = {}
for (var i = 0; i < vertices.length; i++) {
color[vertices[i]] = 'white'
}
return color
}
this.bfs = function(v, callback) {
var color = initColor()
var queue = new Queue()
queue.enqueue(v)
var d = {}
var pred = {}
for (var i = 0; i < vertices.length; i++) {
d[vertices[i]] = 0
pred[vertices[i]] = null
}
while (!queue.isEmpty()) {
var now = queue.dequeue()
var bian = adjList[now]
for (var i = 0; i < bian.length; i++) {
var w = bian[i]
if (color[w] === 'white') {
color[w] = 'gray'
//設定回點
pred[w] = now
d[w] = d[now] + 1
queue.enqueue(w)
}
}
color[now] = 'black'
if (callback) {
callback(now)
}
}
return {
pred: pred,
d: d
}
}
}
var g = new Graph()
g.addVertices('A')
g.addVertices('B')
g.addVertices('C')
g.addVertices('D')
g.addVertices('E')
g.addVertices('F')
g.addEdge('A', 'B')
g.addEdge('A', 'C')
g.addEdge('A', 'D')
g.addEdge('B', 'E')
g.addEdge('B', 'F')
g.addEdge('C', 'D')
複製程式碼例項化
程式碼實現A-F的最短路徑
var Queue = function() {
var items = [];
//入隊
this.enqueue = function(el) {
items.push(el)
}
//出隊
this.dequeue = function() {
return items.shift();
}
// 隊頭
this.front = function() {
return items[0]
}
//隊是否為空
this.isEmpty = function() {
return items.length === 0;
}
//隊的長度
this.size = function() {
return items.length;
}
}
var Graph = function() {
//儲存頂點
var vertices = []
//邊
var adjList = {}
//新增頂點
this.addVertices = function(v) {
vertices.push(v)
adjList[v] = []
}
// 新增邊
this.addEdge = function(a, b) {
adjList[a].push(b)
adjList[b].push(a)
}
this.print = function() {
var s = '\n';
for (var i = 0; i < vertices.length; i++) {
var dingdian = vertices[i]
s += dingdian + '=>'
var bian = adjList[dingdian]
for (var j = 0; j < bian.length; j++) {
s += bian[j]
}
s += '\n'
}
console.log(s)
}
//white 未發現
//gray 已發現未探索
//black 已探索
var initColor = function() {
var color = {}
for (var i = 0; i < vertices.length; i++) {
color[vertices[i]] = 'white'
}
return color
}
this.bfs = function(v, callback) {
var color = initColor()
var queue = new Queue()
queue.enqueue(v)
var d = {}
var pred = {}
for (var i = 0; i < vertices.length; i++) {
d[vertices[i]] = 0
pred[vertices[i]] = null
}
while (!queue.isEmpty()) {
var now = queue.dequeue()
var bian = adjList[now]
for (var i = 0; i < bian.length; i++) {
var w = bian[i]
if (color[w] === 'white') {
color[w] = 'gray'
//設定回點
pred[w] = now
d[w] = d[now] + 1
queue.enqueue(w)
}
}
color[now] = 'black'
if (callback) {
callback(now)
}
}
return {
pred: pred,
d: d
}
}
}
var g = new Graph()
g.addVertices('A')
g.addVertices('B')
g.addVertices('C')
g.addVertices('D')
g.addVertices('E')
g.addVertices('F')
g.addEdge('A', 'B')
g.addEdge('A', 'C')
g.addEdge('A', 'D')
g.addEdge('B', 'E')
g.addEdge('B', 'F')
g.addEdge('C', 'D')
// g.print()
g.addEdge('D', 'F')
var s = g.bfs("A")
var zuiduan = function(from, to) {
var v = to; //設定當前點
while (v != from) {
console.log(v)
v = s.pred[v]
}
console.log(v)
}
zuiduan("A", "F")
複製程式碼例項化
利用棧(Stack)優化列印順序
var Stack = function() {
var items = [];
// this.items = [];
this.push = function(val) {
items.push(val)
}
this.pop = function() {
return items.pop()
}
this.peek = function() {
return items[items.length - 1]
}
this.isEmpty = function() {
return items.length === 0
}
this.size = function() {
return items.length
}
this.clear = function() {
items = []
}
}
//省略
var s = g.bfs("A")
var zuiduan = function(from, to) {
var v = to; //設定當前點
var path = new Stack()
while (v != from) {
path.push(v)
v = s.pred[v]
}
path.push(v)
var str = ''
while (!path.isEmpty()) {
str += path.pop() +  '-'
}
str = str.slice(0, str.length - 1)
console.log(str)
}
zuiduan("A", "F")
複製程式碼最短路徑: 深度優先
//深度優先
var dfsVisite = function(u, color, callback) {
color[u] = 'gray'
var n = adjList[u]
for (var i = 0; i < n.length; i++) {
var w = n[i]
if (color[w] === 'white') {
dfsVisite(w, color, callback)
}
}
color[u] = 'black'
if (callback) {
callback(u)
}
}
this.dfs = function(v, callback) {
var color = initColor()
dfsVisite(v, color, callback)
}
複製程式碼