主要思想：利用了贪心属性，它有最优子结构，即它的导出子图也是最小生成树。

#include 
     
      using namespace std;const int nmax= 100;int e[nmax][nmax];const int inf = 1 << 20;int MST_Prime(int e[][nmax], int n) {    int book[nmax], dis[nmax],sum=0;    memset(book, 0, sizeof(book));    for (int i = 1; i <= n; i++)        dis[i] = inf;        int flag = 1;    dis[flag] = 0;    book[flag] = 1;    int t = n-1;    while (t--) {        for (int i = 1; i <= n; i++)            if (book[i] == 0 && e[flag][i] < dis[i])                dis[i] = e[flag][i];                        int tmp = inf;        for(int i=1;i<=n;i++)            if (book[i]==0&&dis[i] < tmp) {                tmp = dis[i];                flag = i;            }        sum += tmp;        book[flag] = 1;    }    return sum;}int main() {    int V, E;    while (cin >> V >> E) {        for(int i=0;i<=V;i++)            for (int j = 0; j <= V; j++) {                if (i == j)e[i][j] = 0;                else e[i][j] = inf;            }                for (int i = 0; i < E; i++) {            int x, y, z;            cin >> x >> y >> z;            e[x][y] = z;            e[y][x] = z;        }        cout << MST_Prime(e, V) << endl;    }}