HDU 1863 畅通工程

http://acm.hdu.edu.cn/showproblem.php?pid=1863

 

解题思路：prim算法，统计所有的点有没有都加入到最小生成树中，有就输出sum值，没有就?

 

 

#include <stdio.h>#include <string.h>#define size 105#define INIT 999999int count;int Graph[size][size];long sum;void Prim(int villige){int i,j;int min,locate;int dist[size];sum=0;bool visited[size];memset(visited,0,sizeof(visited));memset(dist,INIT,sizeof(dist));for(i=1;i<=villige;i++)dist[i] = Graph[1][i];visited[i] = true;count = 1;for (j=2;j<=villige;j++){min = INIT;for(i=2;i<=villige;i++){if (!visited[i]&&dist[i]<min){min = dist[i];locate = i;}}if(min!=INIT){visited[locate] = true;sum+=min;count++;for (i=1;i<=villige;i++){if(!visited[i]&&Graph[locate][i]!=0&&dist[i]>Graph[locate][i])dist[i] = Graph[locate][i];}}elsereturn ;}}int main(){int road,villige;int i,j,weight;while (scanf("%d%d",&road,&villige)!=EOF&&road){count = 0;for(i=0;i<=villige;i++){for(j=0;j<=villige;j++)if(i==j)Graph[i][j] = 0;elseGraph[i][j] = INIT;}while (road--){scanf("%d%d%d",&i,&j,&weight);Graph[i][j] = weight;Graph[j][i] = weight;}Prim(villige);if(count==villige)printf("%ld/n",sum);elseprintf("?/n");}return 0;}