Dijkstra （邻接矩阵的另一种实现）

注意  区别于上一个Dijkstra的实现  这里利用 edge[0][j] 值 对 dist 赋值 

核心算法:

//本例 默认 起始点为 0  void Dijkstra(Graph g){int i, j;for (i = 0; i < g.vex_num; i++) {dist[i] = g.edge[0][i];//    关键  ， 0可以为任意顶点 path[i] = -1;known[i] = 0;}int min;int u, v;//算法核心 for (i = 0; i < g.vex_num - 1; i++) {//顶点数少一次 一定可以遍历所有顶点了 min = INFINITY;for (j = 0; j < g.vex_num; j++) {if (dist[j] < min && known[j] == 0) {u = j;min = dist[j];}}known[u] = 1;for (v = 0; v < g.vex_num; v++){if (g.edge[u][v] < INFINITY && dist[v] > dist[u] + g.edge[u][v] && known[v] == 0){dist[v] = dist[u] + g.edge[u][v];path[v] = u;} }}//打印 长度 for(i = 0; i < g.vex_num; i++ ){printf("%5d",dist[i]); }}

完整实现:

#include<stdio.h>#include<stdlib.h>#define MAXVEX 100#define INFINITY 65535int path[MAXVEX];int known[MAXVEX];int dist[MAXVEX];typedef struct Graph {int vex[MAXVEX];int edge[MAXVEX][MAXVEX];int vex_num, edge_num;}Graph;void init_graph(Graph *g) //  重要： c 语言 值传递的特性 必须传递 指针 {int i, j;for (i = 0; i < g->vex_num; i++) {for (j = 0; j < g->vex_num; j++) {if (i == j)g->edge[i][j] = 0;elseg->edge[i][j] = INFINITY;}}}void create_graph(Graph *g){int i, j, k, w;scanf("%d%d",&g->vex_num,&g->edge_num);for (i = 0; i < g->vex_num; i++){scanf("%d",&g->vex[i]);}init_graph(g);for (k = 0; k < g->edge_num; k++) {scanf("%d%d%d", &i, &j, &w);g->edge[i][j] = w;//g->edge[j][i] = w; //也可以是无向图 }}//本例 默认 起始点为 0  void Dijkstra(Graph g){int i, j;for (i = 0; i < g.vex_num; i++) {dist[i] = g.edge[0][i];//    关键  ， 0可以为任意顶点 path[i] = -1;known[i] = 0;}int min;int u, v;//算法核心 for (i = 0; i < g.vex_num - 1; i++) {//顶点数少一次 一定可以遍历所有顶点了 min = INFINITY;for (j = 0; j < g.vex_num; j++) {if (dist[j] < min && known[j] == 0) {u = j;min = dist[j];}}known[u] = 1;for (v = 0; v < g.vex_num; v++){if (g.edge[u][v] < INFINITY && dist[v] > dist[u] + g.edge[u][v] && known[v] == 0){dist[v] = dist[u] + g.edge[u][v];path[v] = u;} }}//打印 长度 for(i = 0; i < g.vex_num; i++ ){printf("%5d",dist[i]); }}void print_graph(Graph g){int i, j;for (i = 0; i < g.vex_num; i++) {for (j = 0; j < g.vex_num; j++) {if(g.edge[i][j] == INFINITY)printf("%5s","*");elseprintf("%5d",g.edge[i][j]);}printf("\n");}}void print_path(Graph g, int end){if(path[end] != -1){print_path(g, path[end]);printf("->");}printf("%d",g.vex[end]);} int main(){Graph g;create_graph(&g);Dijkstra(g);//print_graph(g);return 0;}