图-无权图-无向图(DFS)

package k_graph.A_Graph.A_DFS;


/**
 * 无向图
 * 深度优先搜索(DFS)
 * 
 * @author Administrator
 *
 */
public class DFSApp {
public static void main(String[] args) {
Graph theGraph = new Graph();
theGraph.addVertex('A');
theGraph.addVertex('B');
theGraph.addVertex('C');
theGraph.addVertex('D');
theGraph.addVertex('E');
theGraph.addVertex('F');
theGraph.addVertex('G');
theGraph.addVertex('H');


theGraph.addEage(0, 1);
theGraph.addEage(1, 2);
theGraph.addEage(2, 5);
theGraph.addEage(0, 3);
theGraph.addEage(3, 4);
theGraph.addEage(4, 5);
theGraph.addEage(5, 7);


System.out.print("Visits: ");
theGraph.dfs();
}
}package k_graph.A_Graph.A_DFS;


/**
 * 图
 * 
 * @author Administrator
 *
 */
public class Graph {
public final int MAX_VERTS = 20;
public Vertex vertexList[];// 顶点数组 list of vertices
public int adjMat[][];// 邻接矩阵 adjacency matrix
public int nVerts;// 当前顶点个数 current number of vertices
public StackX theStackX;


public Graph() {
vertexList = new Vertex[MAX_VERTS];
adjMat = new int[MAX_VERTS][MAX_VERTS];
nVerts = 0;
for (int i = 0; i < MAX_VERTS; i++) {
for (int j = 0; j < MAX_VERTS; j++) {
adjMat[i][j] = 0;
}
}
theStackX = new StackX();
}


/**
* 添加顶点
* 
* @param lab
*/
public void addVertex(char lab) {
vertexList[nVerts++] = new Vertex(lab);
}


/**
* 添加边
* 
* @param start
* @param end
*/
public void addEage(int start, int end) {
adjMat[start][end] = 1;
adjMat[end][start] = 1;
}


/**
* 显示对应索引的顶点值
* 
* @param v
*/
public void displayVertex(int v) {
System.out.println(vertexList[v].label);
}


public void dfs() {// depth-first-serch深度优先搜索
vertexList[0].wasVisited = true;
displayVertex(0);
// 下标入栈
theStackX.push(0);
// 深度搜索
while (!theStackX.isEmpty()) {
int v = getAdjUnvisitedVertex(theStackX.peek());// 获取未访问的顶点
if (v != -1) {
// 更改访问状态
vertexList[v].wasVisited = true;
displayVertex(v);
theStackX.push(v);
} else
theStackX.pop();


}
// 重置访问状态
for (int i = 0; i < nVerts; i++) {
vertexList[i].wasVisited = false;
}


}


/**
* 查询未访问过得顶点
* 
* @param v
* @return
*/
public int getAdjUnvisitedVertex(int v) {
int i = -1;
for (int j = 0; j < nVerts; j++) {
// adjMat[v][j] == 1说明有2顶点关联,同时从当前行寻找j循环的数据
// vertexList[j].wasVisited == false说明顶点没访问
if (adjMat[v][j] == 1 && vertexList[j].wasVisited == false) {
i = j;
break;
}
}
return i;
}
}package k_graph.A_Graph.A_DFS;


public class StackX {
public final int SIZE = 20;
public int[] st;
public int top;


public StackX() {
st = new int[SIZE];
top = -1;
}


public void push(int j) {
st[++top] = j;
}


public int peek() {
return st[top];
}


public int pop() {
return st[top--];
}


public boolean isEmpty() {
return top == -1;
}
}package k_graph.A_Graph.A_DFS;


/**
 * 顶点
 * 
 * @author Administrator
 *
 */
public class Vertex {
public char label;
public boolean wasVisited;// false表示没有找到，true表示找到


public Vertex(char label) {
this.label = label;
wasVisited = false;
}


}