图的广度遍历（BFS)与深度遍历(DFS)

转载注明出处，原文地址：http://blog.csdn.net/powerwoo25/article/details/47869457

图的广度遍历（BFS)与深度遍历(DFS)

思路： 读取用户输入的结点个数、边的两端顶点，用一个邻接矩阵来代表图内的连通情况。然后取第一个结点放入双端队列中进行BFS

转载注明出处，原文地址：http://blog.csdn.net/powerwoo25/article/details/47869457
/* BFS */
#include <stdio.h>
#include <deque>
using namespace std;

typedef struct node
{
    int flag, d, pre;
    node(): flag(0), d(10000), pre(-1){};
}vertex;

const int maxV = 10000;
int matrix[maxV][maxV];

void ReadEdge(int num)
{
    int startV, endV;
    printf("Enter your edges:\n");
    while(~scanf("%d,%d", &startV, &endV) && (startV < num) && (startV >= 0) && (endV < num) && (endV >= 0))
    {
        matrix[startV][endV] = matrix[endV][startV] = 1;
    }
}

void BFS(deque<int> Q, vertex *A, int num)
{
    int i;
    A[0].flag = 1;
    A[0].d = 0;

    Q.push_back(0);

    while(!Q.empty())
    {
        int u = Q.front();
        Q.pop_front();
        for(i = 0; i < num; i++)
        {
            if(matrix[u][i] != 0 && A[i].flag == 0)
            {
                A[i].flag = 1;
                A[i].d = A[u].d + 1;
                A[i].pre = u;
                Q.push_back(i);
            }
        }
        A[u].flag = 2;
    }
}

void PrintVertex(vertex* A, int num)
{
    int i, j, k;

    for(j = 0; j < num; ++j)
    {
        for(k = 0; k < num; ++k)
        {
            printf("%d ", matrix[j][k]);
        }
        printf("\n");
    }
    for(i = 0; i < num; ++i)
    {
        printf("Vertex: %d, flag: %d, pre: %d, d: %d\n", i, A[i].flag, A[i].pre, A[i].d);
    }
}

int main()
{
    freopen("J://test.txt", "r", stdin);

    int vertexN;
    printf("Please enter the quantity of your vertex\n");
    scanf("%d", &vertexN);
    if(vertexN < 1 || vertexN > maxV)
    {
        perror("Invalid parameter: vertexN\n");
        return -1;
    }
    vertex vertexs[vertexN];

    ReadEdge(vertexN);

    deque<int> vertexQ;
    vertexQ.clear();

    BFS(vertexQ, vertexs, vertexN);

    PrintVertex(vertexs, vertexN);

    return 0;
}

思路：DFS主要利用递归来进行深度优先的遍历

转载注明出处，原文地址：http://blog.csdn.net/powerwoo25/article/details/47869457
/* DFS */
#include <stdio.h>
using namespace std;

 typedef struct node
{
    int flag;
    int pre;
    int d, f;
    node(): flag(0), pre(-1), d(0), f(0){};
}vertex;

const int maxV = 10000;
int time = 0;
int matrix[maxV][maxV];

void ReadEdge(int num)
{
    int startV, endV;
    printf("Enter your edges:\n");
    while(~scanf("%d,%d", &startV, &endV) && (startV < num) && (startV >= 0) && (endV < num) && (endV >= 0))
    {
        matrix[startV][endV] = matrix[endV][startV] = 1;
    }
}

void PrintVertex(vertex* A, int num)
{
    int i, j, k;

    for(j = 0; j < num; ++j)
    {
        for(k = 0; k < num; ++k)
        {
            printf("%d ", matrix[j][k]);
        }
        printf("\n");
    }
    for(i = 0; i < num; ++i)
    {
        printf("Vertex: %d, flag: %d, pre: %d, d: %d, f: %d\n", i, A[i].flag, A[i].pre, A[i].d, A[i].f);
    }
}

void DFS_VISIT(vertex *A, int index, int num)
{
    int i;
    A[index].d = ++time;
    A[index].flag = 1;
    for(i = 0; i < num; ++i)
    {
        if(matrix[index][i] != 0)
        {
            if(A[i].flag == 0)
            {
                A[i].pre = index;
                DFS_VISIT(A, i, num);
            }
        }
    }
    A[index].flag = 2;
    A[index].f = ++time;
}

void DFS(vertex *A, int num)
{
    int i;
    for(i = 0; i < num; ++i)
    {
        if(A[i].flag == 0)
        {
            DFS_VISIT(A, i, num);
        }
    }
}

int main()
{
    freopen("J://test.txt", "r", stdin);
    int vertexN;
    printf("Please enter the quantity of your vertex\n");
    scanf("%d", &vertexN);
    if(vertexN < 1 || vertexN > maxV)
    {
        perror("Invalid parameter: vertexN\n");
        return -1;
    }
    vertex vertexs[vertexN];

    ReadEdge(vertexN);

    DFS(vertexs, vertexN);

    PrintVertex(vertexs, vertexN);

    return 0;
}

# test.txt100,23,42,44,13,15,62,67,93,88,9