弗洛伊德算法，最短路径长度正确，但是最短路径结果path最后会出现重复

fxbbing 2015-07-09 03:50:57

#define maxsize 92

#include<stdio.h>

#include<math.h>

typedef struct{

	double arcs[maxsize][maxsize];

	int vexNum;

}MGraph;

typedef struct{

	double x,y;

}Point;

void floyd(MGraph G);

int main()

{

	int x, y;

	MGraph graph;

	Point point[maxsize];

	graph.vexNum = maxsize;

	//初始化

	for (int i = 0; i < graph.vexNum; i++)

		for (int j = 0; j < graph.vexNum; j++)

		{

			graph.arcs[i][j]=10000;

			if (i == j)

				graph.arcs[i][j] = 0;

		}

	printf("请输入顶点坐标：\n");

	for (int i = 0; i < graph.vexNum; i++)

	{

		scanf("%lf%lf", &point[i].x, &point[i].y);

	}

	printf("请输入相邻顶点标号：(0 0结束)\n");

	while (1)

	{

		scanf("%d%d",&x,&y);

		if (x == 0 && y == 0)

			break;

		else{

			graph.arcs[x - 1][y - 1] = sqrt((point[x - 1].x - point[y - 1].x)*(point[x - 1].x - point[y - 1].x) + (point[x - 1].y - point[y - 1].y)*(point[x - 1].y- point[y - 1].y));

			graph.arcs[y - 1][x - 1] = sqrt((point[x - 1].x - point[y - 1].x)*(point[x - 1].x - point[y - 1].x) + (point[x - 1].y - point[y - 1].y)*(point[x - 1].y - point[y - 1].y));

		}

	}

	floyd(graph);

}

void floyd(MGraph G)

{

	int i, j, k, m, n;

	double d[maxsize][maxsize];

	int path[maxsize][maxsize][maxsize];

	//初始化

	for (i = 0; i < G.vexNum; i++)

		for (j = 0; j < G.vexNum; j++)

		{

			d[i][j] = G.arcs[i][j];

			for (k = 0; k < G.vexNum; k++)

				path[i][j][k] = -1;

		}

	//存放初始路径

	for (i = 0; i < G.vexNum; i++)

		for (j = 0; j < G.vexNum; j++)

			if (d[i][j] != 10000 && d[i][j] != 0)

			{

				path[i][j][0] = i;

				path[i][j][1] = j;

			}

	//迭代

	for (k = 0; k < G.vexNum; k++)

	{

		for (i = 0; i < G.vexNum; i++)

			for (j = 0; j < G.vexNum; j++)

				if (d[i][k] != 0 && d[i][k] != 10000 && d[k][j] != 0 && d[k][j] !=10000&& d[i][k] + d[k][j] < d[i][j])

				{

					d[i][j] = d[i][k] + d[k][j];

					for (m = 0; m < G.vexNum; m++)

					{

						if (path[i][k][m] != -1)

							path[i][j][m] = path[i][k][m];

						else

							break;

					}

					for (n = 1; n < G.vexNum; n++)

					{

						if (path[k][j][n] != -1)

							path[i][j][m++] = path[k][j][n];

						else

							break;

					}

				}

	}

	//输出结果



	printf("最短路径长度:\n");

	for (m = 0; m < G.vexNum; m++)

	{

		for (n = 0; n < 20; n++)

			printf("%6.2lf",d[m][n]);

		printf("\n");

	}

	/*printf("最短路径");

	for (i = 0; i < G.vexNum; i++)

	{

		for (j = 0; j < G.vexNum; j++)

		{

			printf("%d-->%d:",i,j);

			for (m = 0; path[i][j].pa[m] != -1; m++)

				printf("%d ", path[i][j].pa[m]);

			if (m != 0)

				printf("\b\b");

			printf("\t\t\t");

		}

		printf("\n");

	}*/

}