6392. [2019.10.26] NOIP2019 analog zombies

Title Description


answer

Shouted questionsBut such a solution to a problem how fans
Consider a different approach and solution to a problem (understanding)
first zombie discrete, identical h Chin (ying) a point size
(this can be found in each case would only be counted just once)
calculation scheme is fully occupied, then 1 - program / probability
due to the size is determined, so eventually be divided into blocks that are not connected, and there is only a block zombie
define a block number is the number of occupied zombies
provided f [i] [x] ( x > 0) denotes the subtree rooted at i is the point where the block number i is x
then for f [j] [y] ( j∈son [i], j> 0) transferred following:
①X Y =
F [J ] [y] (x zombie through i - j is the number of programs) -> f [i] [ x]
then x and y in a zombie only one block in the same block, since the block it is necessary to communicate
② X <y
F [j] [y]
(y zombies without i - j is the number of programs) -> F [I] [x]
x and y are not in the same block, so that x and y can not be connected, i.e., zombie larger (y) can not go to the other point (i)
and to ensure the presence of y j, x is not present , the reasons below
③ X-> Y
F [J] [Y] * (x zombies without i-- j is the number of programs) -> f [i] [ x]
Cause & scope supra

The initial value f [i] [x] = [x> = h [i]] (x> 0)

Restrictions ②③ of:
as to ensure that just the presence of the zombie to a point x i is the shallowest point of the block ,
ensures that when i and FA [i] is disconnected x subtree i of the leaves, where the block i son leaves the block to ensure the disconnect x is not outside the block , the block must be present so that x

Time complexity of O (n ^ 3), the prefix and suffix optimized to O (n ^ 2)

code

#include <algorithm>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <bitset>
#include <cstdio>
#define fo(a,b,c) for (a=b; a<=c; a++)
#define fd(a,b,c) for (a=b; a>=c; a--)
#define add(a,b) a=((a)+(b))%998244353
#define min(a,b) (a<b?a:b)
#define max(a,b) (a>b?a:b)
#define mod 998244353
#define Mod 998244351
using namespace std;

struct type{
    int x,id;
} b[2001];
int a[4002][2];
int c[2001][2001];
int C[2001];
int ls[2001];
int L[2001];
int R[2001];
int h[2001];
int H[2001];
long long f[2001][2001];
long long s1[2002];
long long s2[2002];
bitset<2001> bz[2001];
int T,N,n,m,i,j,k,l,len;
long long ans,s;

bool cmp(type a,type b)
{
    return a.x<b.x;
}

void New(int x,int y)
{
    ++len;
    a[len][0]=y;
    a[len][1]=ls[x];
    ls[x]=len;
}

long long qpower(long long a,int b)
{
    long long ans=1;
    
    while (b)
    {
        if (b&1)
        ans=ans*a%mod;
        
        a=a*a%mod;
        b>>=1;
    }
    
    return ans;
}

void Dfs(int Fa,int t)
{
    int i;
    
    if (h[t]) bz[t][h[t]]=1;
    
    for (i=ls[t]; i; i=a[i][1])
    if (a[i][0]!=Fa)
    {
        Dfs(t,a[i][0]);
        bz[t]|=bz[a[i][0]];
    }
}

void dfs(int Fa,int t)
{
    int i,j,k,l,id;
    long long x;
    
    fo(i,max(1,h[t]),N) f[t][i]=1;
    
    for (i=ls[t]; i; i=a[i][1])
    if (a[i][0]!=Fa)
    {
        id=i/2;
        dfs(t,a[i][0]);
        
        fo(k,1,N)
        {
            s1[k]=s1[k-1];
            
            if (bz[a[i][0]][k])
            add(s1[k],f[a[i][0]][k]);
        }
        s2[N+1]=0;
        fd(k,N,1)
        {
            s2[k]=s2[k+1];
            
            if (bz[a[i][0]][k])
            add(s2[k],f[a[i][0]][k]*max(R[id]-max(H[k],L[id])+1,0)%mod);
        }
        
        fo(j,1,N)
        {
            if (!bz[a[i][0]][j])
            f[t][j]=f[t][j]*(s2[j+1]+s1[j-1]*max(R[id]-max(H[j],L[id])+1,0)%mod+f[a[i][0]][j]*max(min(H[j]-1,R[id])-L[id]+1,0)%mod)%mod;
            else
            f[t][j]=f[t][j]*(f[a[i][0]][j]*max(min(H[j]-1,R[id])-L[id]+1,0)%mod)%mod;
            
//          O(n^3)
//          fo(k,1,N)
//          if (f[a[i][0]][k])
//          {
//              if (j<k)
//              x=max(R[id]-max(H[k],L[id])+1,0);
//              if (j==k)
//              x=max(min(H[k]-1,R[id])-L[id]+1,0);
//              if (j>k)
//              x=max(R[id]-max(H[j],L[id])+1,0);
//              
//              if (j==k || bz[a[i][0]][k] && !bz[a[i][0]][j])
//              add(F[j],f[t][j]*f[a[i][0]][k]%mod*x);
//          }
        }
    }
}

int main()
{
    freopen("zombie.in","r",stdin);
    freopen("zombie.out","w",stdout);
    
    scanf("%d",&T);
    for (;T;--T)
    {
        memset(bz,0,sizeof(bz));
        memset(ls,0,sizeof(ls));
        memset(h,0,sizeof(h));
        memset(H,0,sizeof(H));
        memset(f,0,sizeof(f));
        memset(C,0,sizeof(C));
        len=1;
        
        scanf("%d%d",&n,&m);
        fo(i,1,n-1)
        {
            scanf("%d%d%d%d",&j,&k,&L[i],&R[i]);
            
            New(j,k);
            New(k,j);
        }
        fo(i,1,m)
        {
            scanf("%d%d",&j,&k);
            h[j]=max(h[j],k);
        }
        
        N=0;
        fo(i,1,n)
        if (h[i])
        b[++N]={h[i],i};
        
        sort(b+1,b+N+1,cmp);
        
        fo(i,1,N)
        {
            H[i]=b[i].x;
            h[b[i].id]=i;
        }
        
        Dfs(0,1);
        dfs(0,1);
        
        ans=0;
        fo(i,1,N)
        add(ans,f[1][i]);
        
        s=1;
        fo(i,1,n-1)
        s=s*(R[i]-L[i]+1)%mod;
        ans=ans*qpower(s,Mod)%mod;
        
        printf("%lld\n",((1-ans)%mod+mod)%mod);
    }
    
    fclose(stdin);
    fclose(stdout);
    
    return 0;
}

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Origin www.cnblogs.com/gmh77/p/11756104.html