洛谷5160 【模板】支配树

坑待填。

sun真的wd发现了题解的bug，顺带叉掉了。

等我研究明白了会把这篇题解填好的。

目前先扔代码跑路。

//Love and Freedom.
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#define inf 20021225
#define ll long long
#define N 200010
#define M 300010
using namespace std;

struct edge{int to,lt;}g[M],f[M],t[N],e[N];
int ig[N],it[N],ie[N],in[N],semi[N],idom[N];
int cnt,cng,cne,cnf,sz[N],n,m; // in -> if
void add(edge E[],int IN[],int &CNT,int x,int y){E[++CNT].to = y; E[CNT].lt = IN[x]; IN[x] = CNT;}
int dfn[N],poi,id[N],fa[N],bel[N],val[N];
void dfs(int x)
{
    dfn[x] = ++poi; id[poi] = x;
    //printf("MDZZ
");
    for(int i=ig[x];i;i=g[i].lt)
    {
        if(dfn[g[i].to])    continue;
        dfs(g[i].to); fa[g[i].to] = x;
    }
}
int find(int x)
{
    if(bel[x] == x)    return x;
    int rt = find(bel[x]);
    if(dfn[semi[val[x]]]>dfn[semi[val[bel[x]]]])    val[x] = val[bel[x]];
    return bel[x] = rt;
}
void tarjan()
{
    for(int i=poi;i>=2;i--)
    {
        int x = id[i];
        for(int j=in[x];j;j=f[j].lt)
        {
            int v = f[j].to; if(!dfn[v])    continue;
            find(v);
            if(dfn[semi[val[v]]]<dfn[semi[x]])
                semi[x] = semi[val[v]];
        }
        add(t,it,cnt,semi[x],x);
        bel[x] = fa[x];
        if(id[i-1] == fa[x])
        {
            x = id[i-1];
            for(int j=it[x];j;j=t[j].lt)
            {
                int v = t[j].to; find(v);// printf("QAQ");
                if(semi[val[v]] == x)    idom[v] = x;
                else    idom[v] = val[v];
            }
        }
    }
    for(int i=2;i<=poi;i++)
    {
        int x = id[i];
        if(idom[x] != semi[x])    idom[x] = idom[idom[x]];
    }
}
void getans(int x)
{
    sz[x] = 1;
    for(int i=ie[x];i;i=e[i].lt)
    {
        int y = e[i].to;// if(!sz[y])
        getans(y);    sz[x] += sz[y];
    }
}

int main()
{
    //freopen("luoguP5180_hackdata.txt","r",stdin);
    //freopen("test.txt","w",stdout);
    scanf("%d%d",&n,&m); int x,y;
    for(int i=1;i<=n;i++)    semi[i] = bel[i] = val[i] = i;
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d",&x,&y);
        add(g,ig,cng,x,y); add(f,in,cnf,y,x);
    }
    dfs(1); tarjan();
    for(int i=2;i<=n;i++)    if(idom[i])
        add(e,ie,cne,idom[i],i);
    getans(1);
    for(int i=1;i<=n;i++)    printf("%d ",sz[i]);
    return 0;
}