HDU 1233 还是畅通问题

 

http://acm.hdu.edu.cn/showproblem.php?pid=1233

 

 

解题思路：用Prim算法求最小生成树，然后输出总权值。

 

#include <stdio.h> #include <string.h> #define size 100 #define INIT 999999 int Graph[size][size]; long sum; void Prim(int N) { int i,j; int min,locate; int dist[size]; bool visited[size]; memset(visited,0,sizeof(visited)); for(i=1;i<=N;i++) dist[i] = Graph[1][i]; visited[1] = true; for (j=2;j<=N;j++) { min = INIT; for (i=1;i<=N;i++) { if (!visited[i]&&dist[i]<min) { min = dist[i]; locate = i; } } sum+=min; visited[locate] = true; for (i=1;i<=N;i++) { if (!visited[i]) { if (dist[i]>Graph[locate][i]) { dist[i] = Graph[locate][i]; } } } } } int main() { int i,j,weight; int N,k; /*freopen("e://1.txt","r",stdin);*/ while (scanf("%d",&N)!=EOF&&N) { sum = 0; for(i=1;i<=N;i++) { for(j=1;j<=N;j++) if(i==j) Graph[i][j] = 0; else Graph[i][j] = INIT; } k = (N*(N-1))/2; while (k--) { scanf("%d%d%d",&i,&j,&weight); Graph[i][j] = weight; Graph[j][i] = weight; } Prim(N); printf("%ld/n",sum); } return 0; }