最小生成树模板

http://acm.fjut.edu.cn/Problem.jsp?pid=1545

FJUTOJ 1545

Prim

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <iostream>

using namespace std;
#define M 105

const int INF=1<<29;

int n,m,arr[M][M];

int prim()
{
    int dis[M],vis[M],i,j,u,ans=0;
    for(i=1;i<=n;i++)
        dis[i]=arr[1][i],vis[i]=0;
    vis[1]=1;
    for(i=1;i<n;i++)
    {
        int mi=INF;
        for(j=1;j<=n;j++)
        {
            if(!vis[j]&&dis[j]<mi)
            {
                mi=dis[j];
                u=j;
            }
        }
        vis[u]=1;
        ans+=dis[u];
        for(j=1;j<=n;j++)
        {
            if(!vis[j]&&arr[u][j]<dis[j])
            {
                dis[j]=arr[u][j];
            }
        }
    }
    return ans;
}

int main()
{
    int i,j,a,b,c;
    while(scanf("%d",&n)&&n)
    {
        for(i=1;i<=n;i++)
        {
            for(j=1;j<=n;j++)
            {
                arr[i][j]=INF;
            }
        }
        scanf("%d",&m);
        while(m--)
        {
            scanf("%d%d%d",&a,&b,&c);
            arr[a][b]=arr[b][a]=min(arr[a][b],c);
        }
        printf("%d
",prim());

    }
    return 0;
}

kruskal

#include<cstdio>
#include<algorithm>
using namespace std;
struct edge
{
    int from,to,cost;
}arr[105*105];
int n,m,pre[105];
void init()
{
    for(int i=1;i<=n;i++)
    {
        pre[i]=i;
    }
}
int findx(int x)
{
    if(pre[x]==x)return x;
    else return pre[x]=findx(pre[x]);
}
void join(int x,int y)
{
    int fx=findx(x),fy=findx(y);
    if(fx==fy)return;
    pre[fy]=fx;
}
bool same(int x,int y)
{
    return findx(x)==findx(y);
}
bool cmp(edge a,edge b)
{
    return a.cost<b.cost;
}
int kruskal()
{
    int ans=0;
    sort(arr+1,arr+1+m,cmp);
    for(int i=1;i<=m;i++)
    {
        if(same(arr[i].from,arr[i].to))
        {
            continue;
        }
        join(arr[i].from,arr[i].to);
        ans+=arr[i].cost;
    }
    return ans;
}
int main()
{
    while(scanf("%d",&n)&&n)
    {
        scanf("%d",&m);
        init();
        for(int i=1;i<=m;i++)
        {
            scanf("%d%d%d",&arr[i].from,&arr[i].to,&arr[i].cost);
        }
        printf("%d
",kruskal());
    }
}