【转载】深度优先搜索代码

#include <iostream>
#define MAXLENGTH 1000
#define WHITE 0
#define GREY 1
#define BLACK 2
using namespace std;
//The color of node. They can be used to define the link type between two nodes. WHITE means the node has not been visited. Gray means the node has been searched but its descendants have not been not all visited. Black means that the node and its descendants have all been visited.
int Color[MAXLENGTH];
//the parent of node i
int Parent[MAXLENGTH];
//the first time to be visited
int StartTime[MAXLENGTH];
//the second time to be visited, after visiting the descendants.
int EndTime[MAXLENGTH];
//the node graph
bool Graph[MAXLENGTH][MAXLENGTH];
//count the time
int time_count;
void DFS_Visit(int, int, int);
/**
 * @brief Dfs graph who has n nodes
 *
 * @param n: the nodes‘ number
 */
void DFS(int n)
{
    //initialization
    for (int i = 0; i < n; ++i)
    {
        Color[i] = WHITE;
    }
    time_count = 0;
    //start DFS visit. Some nodes may can‘t be visited if starts from some nodes, so loop to ensure that every node can be visited.
    for (int i = 0; i < n; ++i)
    {
        if (Color[i] == WHITE)
        {
            DFS_Visit(i, -1, n);
        }
    }
}
/**
 * @brief DFS visit node
 *
 * @param node: the node to be visited
 * @param parent: the parent of the node
 * @param n: the nodes number in the graph
 */
void DFS_Visit(int node, int parent, int n)
{
    Color[node] = GREY;
    Parent[node] = parent;
    StartTime[node] = time_count++;
    for (int i = 0; i < n; ++i)
    {
        if (Graph[node][i] && Color[i] == WHITE)
        {
            DFS_Visit(i, node, n);
        }
    }
    Color[node] = BLACK;
    EndTime[node] = time_count++;
}
/**
 * @brief Print the path from start to end
 *
 * @param end: the end node
 */
void PrintPath(int end)
{
    cout << "Show path from end to start" << endl;
    while (end != -1)
    {
        cout << end << " start-time:" << StartTime[end] << "   end-time:" << EndTime[end] << endl;
        end = Parent[end];
    }
}
int main()
{
    int n;
    while (cin >> n, n != 0)
    {
        for (int i = 0; i < n; ++i)
        {
            for (int j = 0; j < n; ++j)
            {
                cin >> Graph[i][j];
            }
        }
        int end;
        DFS(n);
        while (cout << "Input the end node, -1 means no more search." << endl, cin >> end, end != -1)
        {
            PrintPath(end);
        }
    }
}