【Prim算法】算法实验题12.2 网络互联问题

做了这个以后发现其实Prim和Dijkstra是有很大的相似之处的。

不同的地方就是在

Prim是这样判断的。

if (Set[i]!=1&&dist[i]>Graph[j][i])

而Dijkstra的是

dist[i]>Graph[j][i]+dist[j]

刚刚开始有点儿搞混掉了。。。。

#include <stdio.h>#include <string.h>#define INFINITE 999999#define NUMOFPOINT 510int Prim(int Graph[][NUMOFPOINT], int n){int i,k,j;int sum;int nearpoint[NUMOFPOINT];int dist[NUMOFPOINT];int Set[NUMOFPOINT];int min;for (i=0;i<=n;i++){nearpoint[i] = 0;dist[i] = INFINITE;Set[i] = 0;}for (i=1;i<=n;i++){dist[i] = Graph[1][i];if (dist[i]!=INFINITE)nearpoint[i] = 1;}for (k=1;k<=n;k++){min = INFINITE;for (i=2;i<=n;i++){if (Set[i]!=1&&dist[i]!=INFINITE)if (dist[i]<min){min = dist[i];j = i;}}Set[j] = 1;for (i=2;i<=n;i++){if (Set[i]!=1&&dist[i]>Graph[j][i]){dist[i] = Graph[j][i];nearpoint[i] = j;}}}sum = 0;for (i=1;i<=n;i++)sum += dist[i];return sum;}int main(){int m,n,i,j;int u,v,w;int dist;int Graph[NUMOFPOINT][NUMOFPOINT];while (scanf("%d", &n)!=EOF){memset(Graph, 0, sizeof(Graph));for (i=1;i<=n;i++)for (j=1;j<=n;j++){if (i==j)Graph[i][j] = 0;elseGraph[i][j] = INFINITE;}scanf("%d", &m);for (i=0;i<m;i++){scanf("%d%d%d", &u,&v,&w);if (Graph[u][v]>w){Graph[u][v] = w;Graph[v][u] = w;}}dist = Prim(Graph, n);if (dist>INFINITE)printf("No Solution/n");elseprintf("%d/n", dist);}return 0;}