BZOJ 4027 兔子与樱花

原来想的是给所有点排序。。。。但是要修改啊。。。然后发现对于儿子排序就可以了。

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
#define maxn 2000050
#define maxv 2000050
#define maxe 4000050
using namespace std;
int n,m,c[maxn],s[maxn],x,top=,ans=,g[maxv],nume=,fath[maxv],tot[maxv];
bool vis[maxn];
struct pnt
{
    int id,rank;
}p[maxn];
struct edge
{
    int v,nxt;
}e[maxe];
struct value
{
    int val,id;
}ret[maxn];
queue <int> q;
int read()
{
    char ch;int data=;
    while (ch<'' || ch>'') ch=getchar();
    while (ch>='' && ch<='')
    {
        data=data*+ch-'';
        ch=getchar();
    }
    return data;
}
bool cmp1(pnt x,pnt y) {return x.rank<y.rank;}
bool cmp2(value x,value y) {return x.val<y.val;}
void addedge(int u,int v)
{
    e[++nume].v=v;
    e[nume].nxt=g[u];
    g[u]=nume;
}
void topusort()
{
    p[].id=;p[].rank=;q.push();
    while (!q.empty())
    {
        int head=q.front();q.pop();
        for (int i=g[head];i;i=e[i].nxt)
        {
            int v=e[i].v;
            p[v].id=v;p[v].rank=p[head].rank+;
            q.push(v);
        }
    }
    sort(p+,p+n+,cmp1);
}
int main()
{
    n=read();m=read();
    for (int i=;i<=n;i++) c[i]=read();
    for (int i=;i<=n;i++)
    {
        s[i]=read();
        for (int j=;j<=s[i];j++)
        {
            x=read();x++;
            addedge(i,x);fath[x]=i;tot[i]+=c[x];
        }
    }
    topusort();
    for (int i=n;i>=;i--)
    {
        top=;int now=p[i].id;
        for (int j=g[now];j;j=e[j].nxt)
        {
            int v=e[j].v;
            ret[++top].val=c[v]+s[v]-;
            ret[top].id=v;
        }
        sort(ret+,ret+top+,cmp2);
        for (int j=;j<=top;j++)
        {
            if (c[now]+s[now]+ret[j].val<=m)
            {
                ans++;
                tot[now]+=tot[ret[j].id];
                c[now]+=c[ret[j].id];
                s[now]+=s[ret[j].id]-;
            }
        }
    }
    printf("%d\n",ans);
    return ;
}