prim和Kruskal算法
prim算法
1 #include <iostream> 2 #include <cstdio> 3 #define max 10 4 using namespace std; 5 typedef struct 6 { 7 int relation[max][max]; 8 int vertix[max]; 9 int Vnum,Rnum; 10 }MGraph; 11 12 int getidx(MGraph *M,int v) 13 { 14 for(int i=0;i<M->Vnum;i++) 15 { 16 if(M->vertix[i]==v) 17 return i; 18 } 19 return -1; 20 } 21 void creat_DQWX(MGraph *M) 22 { 23 scanf("%d%d",&M->Vnum,&M->Rnum); 24 for(int i=0;i<M->Vnum;i++) 25 { 26 scanf("%d",&M->vertix[i]); 27 } 28 for(int i=0;i<M->Vnum;i++) 29 { 30 for(int j=0;j<M->Vnum;j++) 31 { 32 M->relation[i][j]=9999; 33 } 34 } 35 for(int i=0;i<M->Rnum;i++) 36 { 37 int v1,v2,w; 38 scanf("%d%d%d",&v1,&v2,&w); 39 int x1 = getidx(M,v1); 40 int x2 = getidx(M,v2); 41 M->relation[x1][x2]=w; 42 M->relation[x2][x1]=w; 43 } 44 } 45 typedef struct 46 { 47 int start; 48 int cost; 49 }closedge; 50 closedge theclose[max]; 51 int mininum(MGraph *M,closedge close[]) 52 { 53 int min = 99999; 54 int min_i = -1; 55 for(int i = 0;i<M->Vnum;i++) 56 { 57 if(close[i].cost>0 && close[i].cost<min) 58 { 59 min = close[i].cost; 60 min_i = i; 61 } 62 } 63 return min_i; 64 } 65 void prim(MGraph *M,int v) 66 { 67 int k = getidx(M,v); 68 for(int i=0;i<M->Vnum;i++) 69 { 70 if(i!=k) 71 { 72 theclose[i].start = k; 73 theclose[i].cost = M->relation[i][k]; 74 } 75 } 76 theclose[k].cost=0; 77 78 for(int i=1;i<M->Vnum;i++) 79 { 80 k = mininum(M,theclose); 81 printf("%d->%d cost:%d\n",M->vertix[theclose[k].start],M->vertix[k],theclose[k].cost); 82 theclose[k].cost = 0; 83 for(int j=0;j<M->Vnum;j++) 84 { 85 if(M->relation[k][j]<theclose[j].cost) 86 { 87 theclose[j].cost = M->relation[k][j]; 88 theclose[j].start = k; 89 } 90 } 91 } 92 } 93 int main() 94 { 95 MGraph M; 96 creat_DQWX(&M); 97 prim(&M,3); 98 }
