6-1 Shortest Path [2]

Write a program to find the weighted shortest distances from any vertex to a given source vertex in a digraph. It is guaranteed that all the weights are positive.

Format of functions:

void ShortestDist( MGraph Graph, int dist[], Vertex S );

where MGraph is defined as the following:

typedef struct GNode *PtrToGNode;
struct GNode{
    int Nv;
    int Ne;
    WeightType G[MaxVertexNum][MaxVertexNum];
};
typedef PtrToGNode MGraph;

The shortest distance from V to the source S is supposed to be stored in dist[V]. If V cannot be reached from S, store -1 instead.
Sample program of judge:

#include <stdio.h>
#include <stdlib.h>

typedef enum {false, true} bool;
#define INFINITY 1000000
#define MaxVertexNum 10  /* maximum number of vertices */
typedef int Vertex;      /* vertices are numbered from 0 to MaxVertexNum-1 */
typedef int WeightType;

typedef struct GNode *PtrToGNode;
struct GNode{
    int Nv;
    int Ne;
    WeightType G[MaxVertexNum][MaxVertexNum];
};
typedef PtrToGNode MGraph;

MGraph ReadG(); /* details omitted */

void ShortestDist( MGraph Graph, int dist[], Vertex S );

int main()
{
    int dist[MaxVertexNum];
    Vertex S, V;
    MGraph G = ReadG();

    scanf("%d", &S);
    ShortestDist( G, dist, S );

    for ( V=0; V<G->Nv; V++ )
        printf("%d ", dist[V]);

    return 0;
}

/* Your function will be put here */

Sample Input (for the graph shown in the figure):

7 9
0 1 1
0 5 1
0 6 1
5 3 1
2 1 2
2 6 3
6 4 4
4 5 5
6 5 12
2
Sample Output:
-1 2 0 13 7 12 3

题中！：不能到达的距离值为-1；
我们把不能抵达的为INFINITY，用过Dijkstra算法，最后记得把INFINITY变成-1，dist[S]变成0。

//AC code
void ShortestDist( MGraph Graph, int dist[], Vertex S )//Dij
{
	int vis[MaxVertexNum]={0};
	vis[S] = 1;
	for(int i = 0;i < Graph->Nv;i++)
	{
		dist[i] = Graph->G[S][i];
	}
	for(int t = 1;t <= Graph->Nv-1;t++)
	{
		int min = INFINITY;
		int temp = INFINITY;
		for( int i = 0;i < Graph->Nv;i++)
		if( !vis[i] && dist[i] <= min )
		min = dist[i],temp = i;
		if( min == INFINITY) continue;
		vis[temp] = 1;
		for(int j = 0;j < Graph->Nv;j++)
		{
			if(!vis[j])
            {
            if(dist[j] > Graph->G[temp][j] + min)
			dist[j] = Graph->G[temp][j] + min;
            }
		} 
			
	}
	for(int i = 0;i < Graph->Nv;i ++)
    if(i == S)dist[i] = 0;
    else if(dist[i] == INFINITY)dist [i] = -1;
}

https://www.cnblogs.com/8023spz/p/7756638.html