如下有向圖 求出單源起點A到所有其他節點的最短路徑

完整程式碼：

#include <stdio.h>
#include <memory.h>
//圖論的迪傑斯特拉演算法
#define FINITY 200
#define M  20
//單源點頂點到其他所有頂點的最短路徑
typedef int edgetype;
typedef int vertextype;
typedef enum{FALSE,TRUE} boolean;
typedef int dist[M];
typedef int path[M];

typedef struct 
{
	edgetype edges[M][M];
	int  vexs[M];
	int n,e;
}Mgraph_t;

void dijkstra(Mgraph_t g,int v0,path p,dist d)
{
	boolean vist[M];
	int i,j,k,v;
	int dmin = FINITY;
	// 1. 初始化集合S 和距離d
	for(v = 0;v < g.n;v++)
	{
		vist[v] = FALSE;
		d[v] = g.edges[v0][v];
	
		if(d[v] < FINITY && d[v] != 0)
			p[v] = v0;
		else
			p[v] = -1;
	}
	vist[v0] = TRUE;d[v0] = 0;

	for(i = 1;i < g.n;i++)
	{
		dmin = FINITY;
		// 2. 在S_V集合中挑選節點
		for(j = 0;j < g.n;j++)
		{
			if(!vist[j] && d[j] < dmin)
			{
				v = j;
				dmin = d[j];
			}
		}
		printf("--- v%d ：dist :%d\n",v,dmin);
		if(dmin == FINITY)
		{
			printf("無\n");
			return ;
		}			
		vist[v] = TRUE;
		// 3. 修改集合S 、S-V 距離d值
		for(k = 0;k < g.n;k++)
		{
			if(!vist[k] && (g.edges[v][k] + dmin < d[k]))
			{
				d[k] = g.edges[v][k] + dmin;
				p[k] = v;
			}
		}	
		for(v = 0;v < g.n;v++)
		{printf("%d:[%d]  ",v,d[v]);}printf("\n");
	}
}
void print_gpd(Mgraph_t g,path p,dist d)
{
	int i = 0; 
	int top = -1;
	int pre = -1;
	int stack[M];
	for(i = 0;i < g.n;i++)
	{
		printf("v0->v%d  dist : %d ",i,d[i]);
		//路徑壓棧
		stack[++top] = i;
		pre = p[i];
		while(pre != -1) 
		{
			stack[++top] = pre;
			pre = p[pre];
		}
		printf("path ：");
		//路勁出棧
		while(top > 0)
		{
			printf("->v%d",stack[top--]);
		}
		printf("\n");
	}
}
void print_matrix(Mgraph_t g)
{
	int i,j;
	for(i = 0;i < g.n;i++)
	{
		for(j = 0;j < g.n;j++)
		{
			//if(g.edges[i][j] == FINITY)
			//	printf("a");
			//else
				printf("%d\t",g.edges[i][j]);
		}
		printf("\n");
	}
}

int main(void)
{
	Mgraph_t g;
	path p;
	dist d;
	int i,j,x,y,dist;
	int v0;
	printf("輸入 頂點數 和 邊數:");
	scanf("%d %d",&g.n,&g.e);
	
	
	for(i = 0;i < g.n;i++)
	{
		for(j = 0;j < g.n;j++)
		{
			g.edges[i][j] = FINITY;
		}
	}
	//memset(&g.edges,200,M*M);
	for(i = 1;i <= g.e;i++)
	{
		printf("輸入第%d條邊：",i);
		scanf("%d %d %d",&x,&y,&dist);
		g.edges[x][y] = dist;
	}
	print_matrix(g);
	printf("輸入起點頂點: \n");
	scanf("%d",&v0);
	dijkstra(g,v0,p,d);
	print_gpd(g,p,d);
	return 0;
}
 

編譯程式碼生成可執行檔案命令

$ gcc Dijkstra.c -o Dijkstra.out
$ ./Dijkstra.out

執行結果