图的广度优先遍历

#include <cstdlib>
#include <cstring>
#include <queue>
#include <list>
#include <cstdio>


typedef unsigned int u_int;

static const u_int s_vertex_num = 8;

enum
{
    WHITE = 0,
    GRAY,
    BLACK
};

struct stVertex
{
    u_int       m_iWeight:1;
    u_int       m_iColor:4;
    u_int       m_iParent:8;
    u_int       m_iDistance;
    stVertex    *adj[s_vertex_num];
    char        m_cId;

    stVertex() : m_iWeight(0),m_iColor(WHITE),m_iDistance(-1)
    {
        memset(adj, 0, s_vertex_num * sizeof(stVertex*));
    }

    stVertex(char id) : m_cId(id),m_iWeight(0),m_iColor(WHITE),m_iDistance(-1)
    {
        memset(adj, 0, s_vertex_num * sizeof(stVertex*));
    }
};


struct stGraph
{
    stVertex    m_Matrix[s_vertex_num];

    void init();
    void bfs(int startIndex);

private:
    void initAdj(stVertex *vertex, char id, const char *ids);
};


void stGraph::initAdj(stVertex *vertex, char id, const char *ids)
{
    vertex->m_cId = id;
    int index = 0;

    for (const char *p = ids; *p; ++p)
    {
        vertex->adj[index++] = &m_Matrix[*p - ‘0‘];
    }
}

// 使用临接链表表示
void stGraph::init()
{
    initAdj(&m_Matrix[0], ‘r‘, "14");
    initAdj(&m_Matrix[1], ‘s‘, "05");
    initAdj(&m_Matrix[2], ‘t‘, "563");
    initAdj(&m_Matrix[3], ‘u‘, "267");
    initAdj(&m_Matrix[4], ‘v‘, "0");
    initAdj(&m_Matrix[5], ‘w‘, "126");
    initAdj(&m_Matrix[6], ‘x‘, "5237");
    initAdj(&m_Matrix[7], ‘y‘, "63");
}


void stGraph::bfs(int startIndex)
{
    std::queue<stVertex*, std::list<stVertex*> > q;

    m_Matrix[startIndex].m_iColor = GRAY;
    m_Matrix[startIndex].m_iDistance = 0;
    m_Matrix[startIndex].m_iParent = -1;
    q.push(&m_Matrix[startIndex]);

    while (!q.empty())
    {
        stVertex *u = q.front();
        q.pop();

        int index = 0;
        stVertex *v = u->adj[index++];
        while (v)
        {
            if (v->m_iColor == WHITE)
            {
                v->m_iColor = GRAY;
                v->m_iDistance = u->m_iDistance + 1;
                v->m_iParent = u->m_cId;
                q.push(v);
            }
            v = u->adj[index++];
        }
        u->m_iColor = BLACK;
        printf("%c, %d, %c\n", u->m_cId, u->m_iDistance, u->m_iParent);
    }
}


int main()
{
    stGraph graph;

    graph.init();
    graph.bfs(1);

    return 0;
}