树和多点可达

zhengwei.hzw · zhengwei.hzw · commit 54789acf17d0 · 2016-10-25T01:24:24.000+08:00
diff --git a/src/Digraph/directedDFS.js b/src/Digraph/directedDFS.js
@@ -0,0 +1,37 @@
+'use strict'
+
+class DirectedDFS {
+    constructor(G, s) {
+        this._marked = []
+        //单点可达
+        if (!Array.isArray(s))
+            this._dfs(G, s)
+        // 多点可达
+        else {
+            s.forEach(w => {
+                if (!this.marked(w))
+                    this._dfs(G, w)
+            })
+        }
+    }
+
+    _dfs(G, v) {
+        if(!G.isV(v))
+            throw new Error('别犯傻, 这个顶点都不存在')
+
+        this._marked.push(v)
+
+        ~~(G.adj(v) || []).forEach(w => {
+            if (!this.marked(w))
+                this._dfs(G, w)
+        })
+
+    }
+
+    marked(v) {
+        return this._marked.includes(v)
+    }
+
+}
+
+module.exports = DirectedDFS
diff --git a/src/Digraph/index.js b/src/Digraph/index.js
@@ -0,0 +1,71 @@
+'use strict'
+
+class Digraph {
+    constructor() {
+        this._E = 0
+        this._V = []
+        // 如果用对象的形式没法区分以 '1' 和 1 做 key
+        this._adjK = []
+        this._adjV = []
+    }
+
+    isV(v) {
+        return this._V.includes(v)
+    }
+
+    V() {
+        return Object.keys(this._V).length
+    }
+
+    E() {
+        return this._E
+    }
+
+
+    addEdge(v, w) {
+
+        let index = this._adjK.indexOf(v)
+
+        if (index > -1) {
+            this._adjV[index].push(w)
+        } else {
+            this._adjK.push(v)
+            this._adjV.push([w])
+        }
+
+        if (!this._V.includes(v))
+            this._V.push(v)
+        if (!this._V.includes(w))
+            this._V.push(w)
+
+        this._E++
+    }
+
+    /**
+     * 由 v 指出的边所连接的所有顶点
+     * @param v
+     * @returns {*}
+     */
+    adj(v) {
+        let index = this._adjK.indexOf(v)
+
+        if (index > -1) {
+            return this._adjV[index]
+        } else {
+            return void 0
+        }
+
+    }
+
+    reverse() {
+        let R = new Digraph()
+
+        this._adjV.forEach((ws, index) => {
+            ws.forEach(w => R.addEdge(w, this._adjK(index)))
+        })
+
+        return R
+    }
+}
+
+module.exports = Digraph
diff --git a/src/Digraph/test-case.js b/src/Digraph/test-case.js
@@ -0,0 +1,71 @@
+'use strict'
+
+
+let assert = require('assert')
+    , Digraph = require('./index')
+    , DirectedDFS = require('./directedDFS')
+
+    , testData = [['4', '2']
+    , ['2', '3']
+    , ['3', '2']
+    , ['6', '0']
+    , ['0', '1']
+    , ['2', '0']
+    , ['11', '12']
+    , ['12', '9']
+    , ['9', '10']
+    , ['9', '11']
+    , ['8', '9']
+    , ['10', '12']
+    , ['11', '4']
+    , ['4', '3']
+    , ['3', '5']
+    , ['7', '8']
+    , ['8', '7']
+    , ['5', '4']
+    , ['0', '5']
+    , ['6', '4']
+    , ['6', '9']
+    , ['7', '6']]
+
+// 测试单点可达
+function test1() {
+    let G = new Digraph()
+
+    testData.forEach(d => G.addEdge(d[0], d[1]))
+    assert.deepStrictEqual(G.V(), 13)
+    assert.deepStrictEqual(G.E(), 22)
+
+    let D1 = new DirectedDFS(G, '1')
+        , D2 = new DirectedDFS(G, '2')
+
+    assert.deepStrictEqual(D1.marked('1'), true)
+    assert.deepStrictEqual(D1.marked(1), false)
+
+    ~~['0', '1', '2', '3', '4', '5'].forEach(v => {
+        assert.deepStrictEqual(D2.marked(v), true)
+    })
+
+
+}
+
+
+// 测试多点可达
+function test2() {
+
+    let G = new Digraph()
+
+    testData.forEach(d => G.addEdge(d[0], d[1]))
+
+    let D = new DirectedDFS(G, ['1', '2', '6'])
+
+    ~~['0', '1', '2', '3', '4', '5', '6', '9', '10', '11', '12'].forEach(v => {
+        assert.deepStrictEqual(D.marked(v), true)
+    })
+}
+
+
+test1()
+test2()
+
+console.log('如果看到这里，恭喜你，测试全过了')
