小Y的炮

【存代码】

#include<bits/stdc++.h>
#define N 1000001
#define MAXN 100001
using namespace std;
int n,m,Mo,h1,top,h,t,ans;
int ru[N],x[N],y[N],w1[N],to[N];
int p[MAXN],w2[MAXN],x2[MAXN];
int es[MAXN],xy[MAXN],f[MAXN];
int df[MAXN],wu[MAXN],st[MAXN],cn[MAXN],rst[MAXN];
int h2,cnt,u,ex;
void Build(int x,int y){
    h1++;
    w1[h1]=p[x];
    p[x]=h1;
    to[h1]=y;
}
bool cmp(int a,int b){
    if(x[a]!=x[b])
        return x[a]<x[b];
    else 
        return y[a]<y[b];
}
void tar(int xx){
    df[xx]=wu[xx]=++ex;
    st[++top]=xx;
    for(int i=p[xx];i;i=w1[i]){
        if(!df[to[i]]){
            tar(to[i]);
            wu[xx]=min(wu[xx],wu[to[i]]);
        }
        else 
            if(!cn[to[i]])
                wu[xx]=min(wu[xx],df[to[i]]);
    }
    if(wu[xx]==df[xx]){
        cn[xx]=++cnt;xy[cnt]++;
        while(st[top]!=xx){
            cn[st[top]]=cnt;
            top--;
            xy[cnt]++;
        }
        top--;
    }
}
int main(){
    scanf("%d%d%d",&n,&m,&Mo);
    for (int i=1;i<=m;i++){
        scanf("%d%d",&x[i],&y[i]);
        Build(x[i],y[i]);
    }
    for (int i=1;i<=n;i++)
        if (!df[i])
            tar(i);
    for (int i=1;i<=m;i++){
        ru[i]=i;
        x[i]=cn[x[i]];
        y[i]=cn[y[i]];
    }
    sort(ru+1,ru+1+m,cmp);
    h1=0;
    memset(p,0,sizeof(p));
    for (int i=1;i<=m;i++)
        if((x[ru[i]]!=y[ru[i]])&&(x[ru[i]]!=x[ru[i-1]]||y[ru[i]]!=y[ru[i-1]])){
        //if (x[ru[i]]!=y[ru[i]])
            //if (x[ru[i]]!=x[ru[i-1]]||y[ru[i]]!=y[ru[i-1]]){
                w2[y[ru[i]]]++;
                Build(x[ru[i]],y[ru[i]]);
            }
    for (int i=1;i<=cnt;i++)
        if (!w2[i]){
            //t++;
            rst[++t]=i;
            f[i]=xy[i];
            x2[i]=1;
            if (f[ans]<f[i])
                ans=i;
        }
    
    while (h<t){
        h++;
        u=rst[h];
        for (int k=p[u];k;k=w1[k]){
            w2[to[k]]--;
            //f[to[k]=min(f[to[k]],f[u]+xy[to[k]);
            if (f[to[k]]<f[u]+xy[to[k]]){
                f[to[k]]=f[u]+xy[to[k]];
                x2[to[k]]=0;
                if (f[ans]<f[to[k]])
                    ans=to[k];
            }
            if (f[to[k]]==f[u]+xy[to[k]])
                x2[to[k]]=(x2[to[k]]+x2[u])%Mo;
            if (!w2[to[k]])
                rst[++t]=to[k];
        }
    }
    for(int i=1;i<=n;i++)
        if (f[i]==f[ans])
            h2=(h2+x2[i])%Mo;
    printf("%d
",f[ans]);
    printf("%d",h2);
    return 0;
}