算法导论 单源最短路径 Dijkstra

#include <stdio.h>#include <stdlib.h>#include <limits.h>#include "FIB.h"//图节点typedef struct VertexNode{char name;int key;VertexNode *p;pFNode pf;}Vertex,*pVertex;//图typedef struct {int vn;int **E;pVertex *V;}Graph,*pGraph;//根据算法导论 图24-6 初始化图pGraph initGraph(){pGraph g=(pGraph)malloc(sizeof(Graph));g->vn=5;pVertex vs=(pVertex)malloc(sizeof(Vertex));vs->name='s';vs->key=0;vs->p=NULL;pVertex vt=(pVertex)malloc(sizeof(Vertex));vt->name='t';vt->key=INT_MAX;vt->p=NULL;pVertex vy=(pVertex)malloc(sizeof(Vertex));vy->name='y';vy->key=INT_MAX;vy->p=NULL;pVertex vx=(pVertex)malloc(sizeof(Vertex));vx->name='x';vx->key=INT_MAX;vx->p=NULL;pVertex vz=(pVertex)malloc(sizeof(Vertex));vz->name='z';vz->key=INT_MAX;vz->p=NULL;g->V=(pVertex*)malloc(g->vn*sizeof(pVertex));g->V[0]=vs;g->V[1]=vt;g->V[2]=vx;g->V[3]=vy;g->V[4]=vz;g->E = (int**)malloc(g->vn*sizeof(int*));for(int i=0;i<g->vn;i++){g->E[i]=(int*)malloc(g->vn*sizeof(int));}for(int i=0;i<g->vn;i++){for(int j=0;j<g->vn;j++){g->E[i][j]=INT_MAX;}}g->E[0][1]=20;g->E[0][2]=5;g->E[1][2]=2;g->E[1][3]=1;g->E[2][1]=3;g->E[2][3]=9;g->E[2][4]=2;g->E[3][4]=4;g->E[4][3]=6;g->E[4][0]=7;return g;}void relax(pGraph g,int u,int v,pFIB h){//无边，不进行松弛if(g->E[u][v]==INT_MAX)return;int sum,uk=g->V[u]->key,vk=g->V[v]->key,ew=g->E[u][v];//根据规则，加上无穷等于无穷if(uk==INT_MAX || ew==INT_MAX)sum=INT_MAX;elsesum=uk+ew;if(vk>sum){g->V[v]->key=sum;g->V[v]->p=g->V[u];FIB_heap_decreaseKey(h,g->V[v]->pf,sum);}}void printKey(pGraph g){for(int i=0;i<g->vn;i++){printf("%c %d\n",g->V[i]->name,g->V[i]->key);}}void main(){pGraph g=initGraph();pFIB h=make_FIB_heap();for(int i=0;i<g->vn;i++){pFNode pf=createNode(g->V[i]->key);g->V[i]->pf=pf;pf->vi=i;FIB_heap_insert(h,pf);}while(h->n>0){pFNode uf=FIB_heap_extract_min(h);int u=uf->vi;for(int v=0;v<g->vn;v++){if(g->E[u][v]<INT_MAX)relax(g,u,v,h);}}printKey(g);getchar();}