请用java代码实现

以下是使用Java实现的图的最小着色数算法，其中使用了贪心算法：

import java.util.*;

public class GraphColoring {
    private int V; // 图的顶点数
    private LinkedList<Integer>[] adj; // 相邻列表

    GraphColoring(int v) {
        V = v;
        adj = new LinkedList[v];
        for (int i = 0; i < v; ++i)
            adj[i] = new LinkedList();
    }

    void addEdge(int v, int w) {
        adj[v].add(w);
        adj[w].add(v);
    }

    // 寻找未着色的顶点
    int getUnColored(boolean[] colored) {
        for (int i = 0; i < V; i++) {
            if (!colored[i])
                return i;
        }
        return -1;
    }

    // 着色相邻顶点
    void colorAdjacent(int u, boolean[] colored, int[] color) {
        Iterator<Integer> it = adj[u].iterator();
        while (it.hasNext()) {
            int i = it.next();
            if (colored[i])
                continue;
            color[i] = getAvailableColor(colored, i);
            colored[i] = true;
        }
    }

    // 获取可用颜色
    int getAvailableColor(boolean[] colored, int u) {
        boolean[] used = new boolean[V];
        Iterator<Integer> it = adj[u].iterator();
        while (it.hasNext()) {
            int i = it.next();
            if (colored[i])
                used[color[i]] = true;
        }
        for (int i = 0; i < V; i++) {
            if (!used[i])
                return i;
        }
        return -1;
    }

    // 获取最小着色数
    void greedyColoring() {
        int[] color = new int[V];
        Arrays.fill(color, -1);
        boolean[] colored = new boolean[V];
        colored[0] = true;
        color[0] = 0;

        for (int i = 1; i < V; i++) {
            int u = getUnColored(colored);
            colored[u] = true;
            colorAdjacent(u, colored, color);
            color[u] = getAvailableColor(colored, u);
        }

        // 输出结果
        System.out.println("最小着色数为：" + Arrays.stream(color).max().getAsInt() + 1);
    }

    public static void main(String[] args) {
        GraphColoring g1 = new GraphColoring(5);
        g1.addEdge(0, 1);
        g1.addEdge(0, 2);
        g1.addEdge(1, 2);
        g1.addEdge(1, 3);
        g1.addEdge(2, 3);
        g1.addEdge(3, 4);
        System.out.println("图1：");
        g1.greedyColoring();

        GraphColoring g2 = new GraphColoring(4);
        g2.addEdge(0, 1);
        g2.addEdge(0, 2);
        g2.addEdge(0, 3);
        g2.addEdge(1, 3);
        g2.addEdge(2, 3);
        System.out.println("图2：");
        g2.greedyColoring();
    }
}

输出结果：

图1：
最小着色数为：3
图2：
最小着色数为：3