08-图7 公路村村通 (30 分)

/*prim算法*/
  1 #include<stdio.h>
#include<stdlib.h>
#define MAX 1002
#define INF 500001

typedef int Vertex;
typedef int Weight;

typedef struct ENode* Edge;
struct ENode {
    Vertex V1;
    Vertex V2;
    Weight W;
};

typedef struct GNode* MGraph;
struct GNode {
    int N;
    int M;
    Vertex G[MAX][MAX];
};
MGraph CreateGraph();
MGraph BuildGraph();
void InsertVertex(MGraph Graph, Edge E);
void Prim(MGraph Graph, Vertex dist[], Vertex parent[]);

int main()
{
    MGraph Graph;
    Vertex dist[MAX], parent[MAX];
    for (int i = 0; i < MAX; i++)
    {
        dist[i] = INF;
        parent[i] = 0;
    }
    Graph = BuildGraph();
    Prim(Graph, dist, parent);
}

MGraph CreateGraph()
{
    MGraph Graph = (MGraph)malloc(sizeof(struct GNode));
    scanf("%d%d", &Graph->N, &Graph->M);
    for (int i = 0; i < Graph->N; i++)
        for (int j = 0; j < MAX; j++)
            Graph->G[i][j] = Graph->G[j][i] = INF;
    return Graph;
}

MGraph BuildGraph()
{
    MGraph G;
    Edge E = NULL;
    E = (Edge)malloc(sizeof(struct ENode));
    G = CreateGraph();
    int i;
    for (i = 0; i < G->M; i++)
    {
        scanf("%d%d%d", &E->V1, &E->V2, &E->W);
        InsertVertex(G, E);
    }
    return G;
}

void InsertVertex(MGraph Graph, Edge E)
{
    Graph->G[E->V1][E->V2] = Graph->G[E->V2][E->V1] = E->W;
}

int FindMinDist(MGraph Graph, Vertex dist[],Vertex parent[]) {
    int v, MinDist = INF, Minv = 0;
    for (v = 0; v <= Graph->N; v++)
    {
        if (dist[v]!=0 && dist[v] < MinDist) {
            MinDist = dist[v];
            Minv = v;
        }
    }
    if (MinDist == INF||Minv==0) return 0;
    return Minv;
}

void Prim(MGraph Graph, Vertex dist[], Vertex parent[])
{
    int i, MST=0, V,cost=0;
    for (i = 0; i <= Graph->N; i++)
    {
        if (Graph->G[1][i] != INF) parent[i] = 1;
        else parent[i] = -1;
        dist[i] = Graph->G[1][i];
    }
    dist[1] = 0;
    while (1) {
        V = FindMinDist(Graph, dist,parent);
        if (V == 0) break;
        cost += dist[V];
        dist[V] = 0;MST++;
        for (i = 0; i < Graph->N; i++)
            if (dist[i] != 0)
                if (Graph->G[V][i] < dist[i])
                {
                    dist[i] = Graph->G[V][i];
                    parent[i] = V;
                }
    }
    if (MST == Graph->N-1) printf("%d", cost);
    else printf("-1
");
}

Kruskal算法:

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