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* Sync recent changes to the revised Word. * Revised the preface chapter * Revised the introduction chapter * Revised the computation complexity chapter * Revised the chapter data structure * Revised the chapter array and linked list * Revised the chapter stack and queue * Revised the chapter hashing * Revised the chapter tree * Revised the chapter heap * Revised the chapter graph * Revised the chapter searching * Reivised the sorting chapter * Revised the divide and conquer chapter * Revised the chapter backtacking * Revised the DP chapter * Revised the greedy chapter * Revised the appendix chapter * Revised the preface chapter doubly * Revised the figures
131 lines
3.7 KiB
Swift
131 lines
3.7 KiB
Swift
/**
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* File: graph_adjacency_matrix.swift
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* Created Time: 2023-02-01
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* Author: nuomi1 (nuomi1@qq.com)
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*/
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import utils
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/* 基于邻接矩阵实现的无向图类 */
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class GraphAdjMat {
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private var vertices: [Int] // 顶点列表，元素代表“顶点值”，索引代表“顶点索引”
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private var adjMat: [[Int]] // 邻接矩阵，行列索引对应“顶点索引”
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/* 构造方法 */
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init(vertices: [Int], edges: [[Int]]) {
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self.vertices = []
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adjMat = []
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// 添加顶点
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for val in vertices {
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addVertex(val: val)
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}
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// 添加边
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// 请注意，edges 元素代表顶点索引，即对应 vertices 元素索引
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for e in edges {
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addEdge(i: e[0], j: e[1])
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}
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}
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/* 获取顶点数量 */
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func size() -> Int {
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vertices.count
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}
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/* 添加顶点 */
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func addVertex(val: Int) {
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let n = size()
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// 向顶点列表中添加新顶点的值
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vertices.append(val)
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// 在邻接矩阵中添加一行
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let newRow = Array(repeating: 0, count: n)
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adjMat.append(newRow)
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// 在邻接矩阵中添加一列
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for i in adjMat.indices {
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adjMat[i].append(0)
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}
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}
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/* 删除顶点 */
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func removeVertex(index: Int) {
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if index >= size() {
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fatalError("越界")
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}
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// 在顶点列表中移除索引 index 的顶点
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vertices.remove(at: index)
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// 在邻接矩阵中删除索引 index 的行
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adjMat.remove(at: index)
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// 在邻接矩阵中删除索引 index 的列
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for i in adjMat.indices {
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adjMat[i].remove(at: index)
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}
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}
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/* 添加边 */
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// 参数 i, j 对应 vertices 元素索引
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func addEdge(i: Int, j: Int) {
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// 索引越界与相等处理
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if i < 0 || j < 0 || i >= size() || j >= size() || i == j {
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fatalError("越界")
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}
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// 在无向图中，邻接矩阵关于主对角线对称，即满足 (i, j) == (j, i)
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adjMat[i][j] = 1
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adjMat[j][i] = 1
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}
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/* 删除边 */
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// 参数 i, j 对应 vertices 元素索引
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func removeEdge(i: Int, j: Int) {
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// 索引越界与相等处理
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if i < 0 || j < 0 || i >= size() || j >= size() || i == j {
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fatalError("越界")
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}
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adjMat[i][j] = 0
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adjMat[j][i] = 0
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}
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/* 打印邻接矩阵 */
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func print() {
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Swift.print("顶点列表 = ", terminator: "")
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Swift.print(vertices)
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Swift.print("邻接矩阵 =")
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PrintUtil.printMatrix(matrix: adjMat)
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}
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}
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@main
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enum GraphAdjacencyMatrix {
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/* Driver Code */
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static func main() {
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/* 初始化无向图 */
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// 请注意，edges 元素代表顶点索引，即对应 vertices 元素索引
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let vertices = [1, 3, 2, 5, 4]
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let edges = [[0, 1], [1, 2], [2, 3], [0, 3], [2, 4], [3, 4]]
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let graph = GraphAdjMat(vertices: vertices, edges: edges)
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print("\n初始化后，图为")
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graph.print()
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/* 添加边 */
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// 顶点 1, 2 的索引分别为 0, 2
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graph.addEdge(i: 0, j: 2)
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print("\n添加边 1-2 后，图为")
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graph.print()
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/* 删除边 */
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// 顶点 1, 3 的索引分别为 0, 1
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graph.removeEdge(i: 0, j: 1)
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print("\n删除边 1-3 后，图为")
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graph.print()
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/* 添加顶点 */
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graph.addVertex(val: 6)
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print("\n添加顶点 6 后，图为")
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graph.print()
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/* 删除顶点 */
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// 顶点 3 的索引为 1
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graph.removeVertex(index: 1)
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print("\n删除顶点 3 后，图为")
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graph.print()
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}
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}
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