【bzoj2753】[SCOI2012]滑雪与时间胶囊

#include<algorithm>
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<queue>
using namespace std;

typedef long long LL;

#define N 1000010

struct edge
{
    LL to,next;
}e[N<<1];
LL head[N<<1];
LL cnt;

struct Node
{
    LL x,y,z;
}a[N<<1];

LL n,m;
LL x,y,z;
LL tot,ans;

LL fa[N],vis[N],q[N];

LL h[N];

int find(LL x)
{
    return fa[x]==x ? x : fa[x]=find(fa[x]);
}

void link(LL x,LL y,LL z)
{
    e[++cnt]=(edge){y,head[x]};
    head[x]=cnt;
    a[cnt]=(Node){x,y,z};
}

int cmp(Node x,Node y)
{
    return h[x.y]>h[y.y] || (h[x.y]==h[y.y] && x.z<y.z);
}

void bfs()
{
    queue<LL>q;
    q.push(1);
    vis[1]=1;
    while (!q.empty())
    {
        LL now=q.front();
        q.pop();
        for (LL i=head[now];i;i=e[i].next)
        {
            LL t=e[i].to;
            if (!vis[t])
            {
                q.push(t);
                vis[t]=1;
                tot++;
            }
        }
    }
}

int main()
{
    scanf("%lld%lld",&n,&m);
    for (LL i=1;i<=n;i++)
        scanf("%lld",&h[i]);
    for (LL i=1;i<=m;i++)
    {
        scanf("%lld%lld%lld",&x,&y,&z);
        if (h[x]>=h[y])
            link(x,y,z);
        if (h[x]<=h[y])
            link(y,x,z);
    }
    bfs();
    printf("%lld ",tot+1);
    for (LL i=1;i<=n;i++)
        fa[i]=i;
    sort(a+1,a+cnt+1,cmp);
    for (LL i=1;i<=cnt;i++)
    {
        x=a[i].x;
        y=a[i].y;
        if (!vis[x] || !vis[y])
            continue;
        LL r1=find(x),r2=find(y);
        if (r1!=r2)
            fa[r1]=r2,ans+=a[i].z;
    }
    printf("%lld\n",ans);
    return 0;
}

　　

#include<algorithm>

#include<iostream>

#include<cstdlib>

#include<cstring>

#include<cstdio>

#include<cmath>

#include<queue>

using namespace std;

 

typedef long long LL;

 

#define N 1000010

 

struct edge

{

    LL to,next;

}e[N<<1];

LL head[N<<1];

LL cnt;

 

struct Node

{

    LL x,y,z;

}a[N<<1];

 

LL n,m;

LL x,y,z;

LL tot,ans;

 

LL fa[N],vis[N],q[N];

 

LL h[N];

 

int find(LL x)

{

    return fa[x]==x ? x : fa[x]=find(fa[x]);

}

 

void link(LL x,LL y,LL z)

{

    e[++cnt]=(edge){y,head[x]};

    head[x]=cnt;

    a[cnt]=(Node){x,y,z};

}

 

int cmp(Node x,Node y)

{

    return h[x.y]>h[y.y] || (h[x.y]==h[y.y] && x.z<y.z);

}

 

void bfs()

{

    queue<LL>q;

    q.push(1);

    vis[1]=1;

    while (!q.empty())

    {

        LL now=q.front();

        q.pop();

        for (LL i=head[now];i;i=e[i].next)

        {

            LL t=e[i].to;

            if (!vis[t])

            {

                q.push(t);

                vis[t]=1;

                tot++;

            }

        }

    }

}

 

int main()

{

    scanf("%lld%lld",&n,&m);

    for (LL i=1;i<=n;i++)

        scanf("%lld",&h[i]);

    for (LL i=1;i<=m;i++)

    {

        scanf("%lld%lld%lld",&x,&y,&z);

        if (h[x]>=h[y])

            link(x,y,z);

        if (h[x]<=h[y])

            link(y,x,z);

    }

    bfs();

    printf("%lld ",tot+1);

    for (LL i=1;i<=n;i++)

        fa[i]=i;

    sort(a+1,a+cnt+1,cmp);

    for (LL i=1;i<=cnt;i++)

    {

        x=a[i].x;

        y=a[i].y;

        if (!vis[x] || !vis[y])

            continue;

        LL r1=find(x),r2=find(y);

        if (r1!=r2)

            fa[r1]=r2,ans+=a[i].z;

    }

    printf("%lld\n",ans);

    return 0;

}