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102 lines
2.6 KiB
Go
102 lines
2.6 KiB
Go
// File: graph_adjacency_matrix.go
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// Created Time: 2023-01-31
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// Author: Reanon (793584285@qq.com)
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package chapter_graph
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import "fmt"
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/* 基于邻接矩阵实现的无向图类 */
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type graphAdjMat struct {
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// 顶点列表，元素代表“顶点值”，索引代表“顶点索引”
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vertices []int
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// 邻接矩阵，行列索引对应“顶点索引”
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adjMat [][]int
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}
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/* 构造函数 */
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func newGraphAdjMat(vertices []int, edges [][]int) *graphAdjMat {
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// 添加顶点
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n := len(vertices)
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adjMat := make([][]int, n)
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for i := range adjMat {
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adjMat[i] = make([]int, n)
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}
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// 初始化图
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g := &graphAdjMat{
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vertices: vertices,
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adjMat: adjMat,
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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 i := range edges {
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g.addEdge(edges[i][0], edges[i][1])
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}
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return g
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}
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/* 获取顶点数量 */
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func (g *graphAdjMat) size() int {
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return len(g.vertices)
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}
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/* 添加顶点 */
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func (g *graphAdjMat) addVertex(val int) {
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n := g.size()
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// 向顶点列表中添加新顶点的值
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g.vertices = append(g.vertices, val)
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// 在邻接矩阵中添加一行
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newRow := make([]int, n)
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g.adjMat = append(g.adjMat, newRow)
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// 在邻接矩阵中添加一列
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for i := range g.adjMat {
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g.adjMat[i] = append(g.adjMat[i], 0)
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}
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}
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/* 删除顶点 */
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func (g *graphAdjMat) removeVertex(index int) {
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if index >= g.size() {
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return
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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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g.vertices = append(g.vertices[:index], g.vertices[index+1:]...)
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// 在邻接矩阵中删除索引 index 的行
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g.adjMat = append(g.adjMat[:index], g.adjMat[index+1:]...)
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// 在邻接矩阵中删除索引 index 的列
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for i := range g.adjMat {
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g.adjMat[i] = append(g.adjMat[i][:index], g.adjMat[i][index+1:]...)
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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 (g *graphAdjMat) addEdge(i, 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 >= g.size() || j >= g.size() || i == j {
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fmt.Errorf("%s", "Index Out Of Bounds Exception")
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}
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// 在无向图中，邻接矩阵沿主对角线对称，即满足 (i, j) == (j, i)
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g.adjMat[i][j] = 1
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g.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 (g *graphAdjMat) removeEdge(i, 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 >= g.size() || j >= g.size() || i == j {
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fmt.Errorf("%s", "Index Out Of Bounds Exception")
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}
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g.adjMat[i][j] = 0
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g.adjMat[j][i] = 0
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}
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/* 打印邻接矩阵 */
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func (g *graphAdjMat) print() {
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fmt.Printf("\t顶点列表 = %v\n", g.vertices)
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fmt.Printf("\t邻接矩阵 = \n")
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for i := range g.adjMat {
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fmt.Printf("\t\t\t%v\n", g.adjMat[i])
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}
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}
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