Interface Graph<N>

Type Parameters:
N - node type | 节点类型
All Known Implementing Classes:
MutableGraph
public interface Graph<N>
Graph - Graph Interface Graph - 图接口

An interface for graph data structures supporting directed and undirected graphs.

支持有向图和无向图的图数据结构接口。

Features | 主要功能:

  • Node operations - 节点操作
  • Edge operations - 边操作
  • Directed/undirected support - 有向/无向支持
  • Adjacency queries - 邻接查询

Usage Examples | 使用示例:

Graph<String> graph = MutableGraph.directed();
graph.addNode("A");
graph.addNode("B");
graph.addEdge("A", "B");

Set<String> neighbors = graph.successors("A");  // [B]
boolean hasEdge = graph.hasEdge("A", "B");     // true

Security | 安全性:

  • Thread-safe: No (interface, implementation-dependent) - 否（接口，取决于实现）
  • Null-safe: No - 否
Since:
JDK 25, opencode-base-collections V1.0.0
Author:
Leon Soo www.LeonSoo.com
See Also:

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Interface
    Description
    static interface 
    Graph.EndpointPair<N>
    Endpoint pair representing an edge.

  • Method Summary

    Modifier and Type
    Method
    Description
    Set<N>
    adjacentNodes(N node)
    Return all adjacent nodes (both successors and predecessors).
    boolean
    allowsSelfLoops()
    Check if this graph allows self-loops.
    int
    degree(N node)
    Return the degree of a node (number of edges incident to it).
    default int
    edgeCount()
    Return the number of edges.
    Set<Graph.EndpointPair<N>>
    edges()
    Return the set of all edges.
    boolean
    hasEdge(N nodeU, N nodeV)
    Check if the edge exists.
    boolean
    hasNode(N node)
    Check if the node exists.
    Set<Graph.EndpointPair<N>>
    incidentEdges(N node)
    Return the edges incident to a node.
    int
    inDegree(N node)
    Return the in-degree of a node (number of incoming edges).
    boolean
    isDirected()
    Check if this graph is directed.
    default int
    nodeCount()
    Return the number of nodes.
    Set<N>
    nodes()
    Return the set of all nodes.
    int
    outDegree(N node)
    Return the out-degree of a node (number of outgoing edges).
    Set<N>
    predecessors(N node)
    Return the predecessors (incoming neighbors) of a node.
    Set<N>
    successors(N node)
    Return the successors (outgoing neighbors) of a node.

  • Method Details

    • isDirected

      boolean isDirected()
      Check if this graph is directed. 检查此图是否有向。
      Returns:
      true if directed | 如果有向则返回 true

    • allowsSelfLoops

      boolean allowsSelfLoops()
      Check if this graph allows self-loops. 检查此图是否允许自环。
      Returns:
      true if allows self-loops | 如果允许自环则返回 true

    • nodes

      Set<N> nodes()
      Return the set of all nodes. 返回所有节点的集合。
      Returns:
      the set of nodes | 节点集合

    • edges

      Set<Graph.EndpointPair<N>> edges()
      Return the set of all edges. 返回所有边的集合。
      Returns:
      the set of edges | 边集合

    • hasNode

      boolean hasNode(N node)
      Check if the node exists. 检查节点是否存在。
      Parameters:
      node - the node | 节点
      Returns:
      true if exists | 如果存在则返回 true

    • successors

      Set<N> successors(N node)
      Return the successors (outgoing neighbors) of a node. 返回节点的后继（出边邻居）。
      Parameters:
      node - the node | 节点
      Returns:
      the set of successors | 后继集合

    • predecessors

      Set<N> predecessors(N node)
      Return the predecessors (incoming neighbors) of a node. 返回节点的前驱（入边邻居）。
      Parameters:
      node - the node | 节点
      Returns:
      the set of predecessors | 前驱集合

    • adjacentNodes

      Set<N> adjacentNodes(N node)
      Return all adjacent nodes (both successors and predecessors). 返回所有邻接节点（后继和前驱）。
      Parameters:
      node - the node | 节点
      Returns:
      the set of adjacent nodes | 邻接节点集合

    • degree

      int degree(N node)
      Return the degree of a node (number of edges incident to it). 返回节点的度数（入射边的数量）。
      Parameters:
      node - the node | 节点
      Returns:
      the degree | 度数

    • inDegree

      int inDegree(N node)
      Return the in-degree of a node (number of incoming edges). 返回节点的入度（入边数量）。
      Parameters:
      node - the node | 节点
      Returns:
      the in-degree | 入度

    • outDegree

      int outDegree(N node)
      Return the out-degree of a node (number of outgoing edges). 返回节点的出度（出边数量）。
      Parameters:
      node - the node | 节点
      Returns:
      the out-degree | 出度

    • hasEdge

      boolean hasEdge(N nodeU, N nodeV)
      Check if the edge exists. 检查边是否存在。
      Parameters:
      nodeU - the source node | 源节点
      nodeV - the target node | 目标节点
      Returns:
      true if exists | 如果存在则返回 true

    • incidentEdges

      Set<Graph.EndpointPair<N>> incidentEdges(N node)
      Return the edges incident to a node. 返回入射到节点的边。
      Parameters:
      node - the node | 节点
      Returns:
      the set of incident edges | 入射边集合

    • nodeCount

      default int nodeCount()
      Return the number of nodes. 返回节点数量。
      Returns:
      the number of nodes | 节点数量

    • edgeCount

      default int edgeCount()
      Return the number of edges. 返回边数量。
      Returns:
      the number of edges | 边数量