最小生成树 prime poj1287
poj1287 裸最小生成树
代码
1 #include "map" 2 #include "queue" 3 #include "math.h" 4 #include "stdio.h" 5 #include "string.h" 6 #include "iostream" 7 #include "algorithm" 8 #define abs(x) x > 0 ? x : -x 9 #define max(a,b) a > b ? a : b 10 #define min(a,b) a < b ? a : b 11 12 using namespace std; 13 14 int arc[55][55]; 15 16 void Prime(int n){ 17 int i,j,k,m; 18 int sumweight = 0; 19 int addnew[55]; 20 int lowcost[55]; 21 for(i=1; i<=n; i++){ 22 addnew[i] = 0; 23 lowcost[i] = arc[1][i]; 24 } 25 addnew[1] = 1; 26 for(i=1; i<n; i++){ 27 k = 0,m = 999999; 28 for(j=2; j<=n; j++){ 29 if(!addnew[j] && lowcost[j]<m){ 30 m = lowcost[j]; 31 k = j; 32 } 33 } 34 sumweight += lowcost[k]; 35 addnew[k] = 1; 36 for(j=2; j<=n; j++){ 37 if(!addnew[j] && arc[k][j]<lowcost[j]) 38 lowcost[j] = arc[k][j]; 39 } 40 } 41 printf("%d\n",sumweight); 42 } 43 44 int main(){ 45 int n,m,i,a,b,c; 46 while(scanf("%d",&n)&&n){ 47 memset(arc,111,sizeof(arc)); 48 scanf("%d",&m); 49 while(m--){ 50 scanf("%d%d%d",&a,&b,&c); 51 if(arc[a][b]>c){ 52 arc[a][b] = c; 53 arc[b][a] = c; 54 } 55 } 56 Prime(n); 57 } 58 return 0; 59 }
