mirror of
https://github.com/krahets/hello-algo.git
synced 2024-12-25 21:36:29 +08:00
e720aa2d24
* 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
130 lines
3.7 KiB
Swift
130 lines
3.7 KiB
Swift
/**
|
||
* File: graph_adjacency_matrix.swift
|
||
* Created Time: 2023-02-01
|
||
* Author: nuomi1 (nuomi1@qq.com)
|
||
*/
|
||
|
||
import utils
|
||
|
||
/* 基于邻接矩阵实现的无向图类 */
|
||
class GraphAdjMat {
|
||
private var vertices: [Int] // 顶点列表，元素代表“顶点值”，索引代表“顶点索引”
|
||
private var adjMat: [[Int]] // 邻接矩阵，行列索引对应“顶点索引”
|
||
|
||
/* 构造方法 */
|
||
init(vertices: [Int], edges: [[Int]]) {
|
||
self.vertices = []
|
||
adjMat = []
|
||
// 添加顶点
|
||
for val in vertices {
|
||
addVertex(val: val)
|
||
}
|
||
// 添加边
|
||
// 请注意，edges 元素代表顶点索引，即对应 vertices 元素索引
|
||
for e in edges {
|
||
addEdge(i: e[0], j: e[1])
|
||
}
|
||
}
|
||
|
||
/* 获取顶点数量 */
|
||
func size() -> Int {
|
||
vertices.count
|
||
}
|
||
|
||
/* 添加顶点 */
|
||
func addVertex(val: Int) {
|
||
let n = size()
|
||
// 向顶点列表中添加新顶点的值
|
||
vertices.append(val)
|
||
// 在邻接矩阵中添加一行
|
||
let newRow = Array(repeating: 0, count: n)
|
||
adjMat.append(newRow)
|
||
// 在邻接矩阵中添加一列
|
||
for i in adjMat.indices {
|
||
adjMat[i].append(0)
|
||
}
|
||
}
|
||
|
||
/* 删除顶点 */
|
||
func removeVertex(index: Int) {
|
||
if index >= size() {
|
||
fatalError("越界")
|
||
}
|
||
// 在顶点列表中移除索引 index 的顶点
|
||
vertices.remove(at: index)
|
||
// 在邻接矩阵中删除索引 index 的行
|
||
adjMat.remove(at: index)
|
||
// 在邻接矩阵中删除索引 index 的列
|
||
for i in adjMat.indices {
|
||
adjMat[i].remove(at: index)
|
||
}
|
||
}
|
||
|
||
/* 添加边 */
|
||
// 参数 i, j 对应 vertices 元素索引
|
||
func addEdge(i: Int, j: Int) {
|
||
// 索引越界与相等处理
|
||
if i < 0 || j < 0 || i >= size() || j >= size() || i == j {
|
||
fatalError("越界")
|
||
}
|
||
// 在无向图中，邻接矩阵关于主对角线对称，即满足 (i, j) == (j, i)
|
||
adjMat[i][j] = 1
|
||
adjMat[j][i] = 1
|
||
}
|
||
|
||
/* 删除边 */
|
||
// 参数 i, j 对应 vertices 元素索引
|
||
func removeEdge(i: Int, j: Int) {
|
||
// 索引越界与相等处理
|
||
if i < 0 || j < 0 || i >= size() || j >= size() || i == j {
|
||
fatalError("越界")
|
||
}
|
||
adjMat[i][j] = 0
|
||
adjMat[j][i] = 0
|
||
}
|
||
|
||
/* 打印邻接矩阵 */
|
||
func print() {
|
||
Swift.print("顶点列表 = ", terminator: "")
|
||
Swift.print(vertices)
|
||
Swift.print("邻接矩阵 =")
|
||
PrintUtil.printMatrix(matrix: adjMat)
|
||
}
|
||
}
|
||
|
||
@main
|
||
enum GraphAdjacencyMatrix {
|
||
/* Driver Code */
|
||
static func main() {
|
||
/* 初始化无向图 */
|
||
// 请注意，edges 元素代表顶点索引，即对应 vertices 元素索引
|
||
let vertices = [1, 3, 2, 5, 4]
|
||
let edges = [[0, 1], [1, 2], [2, 3], [0, 3], [2, 4], [3, 4]]
|
||
let graph = GraphAdjMat(vertices: vertices, edges: edges)
|
||
print("\n初始化后，图为")
|
||
graph.print()
|
||
|
||
/* 添加边 */
|
||
// 顶点 1, 2 的索引分别为 0, 2
|
||
graph.addEdge(i: 0, j: 2)
|
||
print("\n添加边 1-2 后，图为")
|
||
graph.print()
|
||
|
||
/* 删除边 */
|
||
// 顶点 1, 3 的索引分别为 0, 1
|
||
graph.removeEdge(i: 0, j: 1)
|
||
print("\n删除边 1-3 后，图为")
|
||
graph.print()
|
||
|
||
/* 添加顶点 */
|
||
graph.addVertex(val: 6)
|
||
print("\n添加顶点 6 后，图为")
|
||
graph.print()
|
||
|
||
/* 删除顶点 */
|
||
// 顶点 3 的索引为 1
|
||
graph.removeVertex(index: 1)
|
||
print("\n删除顶点 3 后，图为")
|
||
graph.print()
|
||
}
|
||
}
|