[Data structures]Floyd

2019-7-30 写技术

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

#define MAX 20
#define INFINIT	65535

typedef struct _MGraph{
	char vexs[MAX];
	int arcs[MAX][MAX];
	int vexnum;
	int arcnum;
}MGraph;

int visited[MAX];

int LocateVex(MGraph *G, char v)
{
	int i=0;
	while(i<G->vexnum && G->vexs[i] != v){
		i++;
	}
	if(i<G->vexnum){
		return i;
	}else{
		return -1;
	}
}

int CreateDN(MGraph *G)
{
	int i,j,k;
	char v1,v2;
	int cost;

	scanf(" %d %d", &G->vexnum, &G->arcnum);	
	for(i=0; i<G->vexnum; i++){
		scanf(" %c", &G->vexs[i] );
	}
	for(i=0; i<G->vexnum; i++){
		for(j=0; j<G->vexnum; j++){
			if(i==j){
				G->arcs[i][j] = 0;
			}else{
				G->arcs[i][j] = INFINIT;
			}
		}
	}
	for(k=0; k<G->arcnum; k++){
		scanf(" %c %c %d", &v1, &v2, &cost);
		i=LocateVex(G, v1);
		j=LocateVex(G, v2);	
		G->arcs[i][j] = cost;
	}
	return 1;
}

int FirstAdjvex(MGraph *G, int v)
{
	int i=0;
	while(i<G->vexnum && G->arcs[v][i] == INFINIT){
		i++;
	}	
	if(i<G->vexnum){
		return i;
	}else{
		return -1;
	}
}

int NextAdjvex(MGraph *G, int v, int w)
{
	int i=w+1;
	while(i<G->vexnum && G->arcs[v][i] == INFINIT){
		i++;
	}
	if(i<G->vexnum){
		return i;
	}else{
		return -1;
	}

}

void Floyd(MGraph *G, int (*P)[MAX][MAX], int (*D)[MAX])
{
	int i;
	int j;
	int k;
	int u;
	
	for(i=0; i<G->vexnum; i++){
		for(j=0; j<G->vexnum; j++){
			D[i][j] = G->arcs[i][j];

			for(u=0; u<G->vexnum; u++){
				P[i][j][u] = 0;
			}
			if(D[i][j] < INFINIT){
				P[i][j][i] = P[i][j][j] = 1;
			}
		}
	}

	for(k=0; k<G->vexnum; k++){
		for(i=0; i<G->vexnum; i++){
			for(j=0; j<G->vexnum; j++){
				if(D[i][j] > D[i][k] + D[k][j]){
					D[i][j] = D[i][k] + D[k][j];

					for(u=0; u<G->vexnum; u++){
						P[i][j][u] = P[i][k][u] || P[k][j][u];
					}
				}
			}
		}
	}
}



void main()
{
	MGraph G;	
	int P[MAX][MAX][MAX];
	int D[MAX][MAX];
	int i,j,u;

	printf("log.anycle.com\n\n");
	printf("Create graph:\n");
	CreateDN(&G);
	for(i=0; i<G.vexnum; i++){
		for(j=0; j<G.vexnum; j++){
			printf(" %5d", G.arcs[i][j]);
		}
		printf("\n");
	}
	printf("\n");

	printf("Floyd:\n");
	Floyd(&G, P, D);

	printf("D:\n");
	for(i=0; i<G.vexnum; i++){
		for(j=0; j<G.vexnum; j++){
			printf(" %5d", D[i][j]);			
		}
		printf("\n");
	}
	printf("\n");

	printf("P:\n");
	for(i=0; i<G.vexnum; i++){
		for(j=0; j<G.vexnum; j++){
			printf("   ");
			for(u=0; u<G.vexnum; u++){
				if(P[i][j][u]){
					printf("%c", G.vexs[u]);
				}else{
					printf(" ");	
				}
			}
		}
		printf("\n");
	}
	printf("\n");

}

标签: Data Structures data_structures

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