1. 程式人生 > >SPOJ.COT2 Count on a tree II(樹上莫隊)

SPOJ.COT2 Count on a tree II(樹上莫隊)

main node return post logs ems truct pri spoj

題目鏈接(同上一題蘋果樹)

為什麽第10個點T了一晚上。。
下面那個卻AC了?跑的也不慢。

TLE:

/*
在DFS序做莫隊 
當一個點不是另一個點的LCA時,需要加上它們LCA的貢獻 
*/
#include <cmath>
#include <cstdio>
#include <cctype>
#include <algorithm>
#define gc() getchar()
//#define gc() (SS==TT&&(TT=(SS=IN)+fread(IN,1,MAXIN,stdin),SS==TT)?EOF:*SS++)
const
int N=5e4+5,M=1e5+5,MAXIN=2e6; int n,m,size,Enum,H[N],nxt[N<<1],to[N<<1],dep[N],fa[N],top[N],son[N],sz[N]; int Now,Ans[M],seq[N<<1],in[N],out[N],id,A[N],ref[N],cnt,tm[N]; //char IN[MAXIN],*SS=IN,*TT=IN; bool vis[N]; struct Ques { int l,r,lca,id; bool operator <(const Ques &a)const
{ return l/size<a.l/size?r<a.r:l/size<a.l/size; } }q[M]; //inline int read() //{ // int now=0,f=1;register char c=gc(); // for(;!isdigit(c);c=gc()) if(c=='-') f=-1; // for(;isdigit(c);now=now*10+c-'0',c=gc()); // return now*f; //} inline void AddEdge(int u,int v) { to[++Enum]=v, nxt[Enum]=H[u], H[u]=Enum; to[++Enum]=u, nxt[Enum]=H[v], H[v]=Enum; } int
Find(int x) { int l=1,r=cnt,mid; while(l<r) if(ref[mid=l+r>>1]>=x) r=mid; else l=mid+1; return l; } void Discrete() { // for(int i=1; i<=n; ++i) A[i]=ref[i]=read(); for(int i=1; i<=n; ++i) scanf("%d",&A[i]),ref[i]=A[i]; std::sort(ref+1,ref+1+n); cnt=1; for(int i=2; i<=n; ++i) if(ref[i]!=ref[i-1]) ref[++cnt]=ref[i]; for(int i=1; i<=n; ++i) A[i]=Find(A[i]); } void Pre_DFS(int x) { in[x]=++id, seq[id]=x, sz[x]=1; int mx=0; for(int v,i=H[x]; i; i=nxt[i]) if((v=to[i])!=fa[x]) { fa[v]=x, dep[v]=dep[x]+1, Pre_DFS(v), sz[x]+=sz[v]; if(sz[v]>mx) mx=sz[v],son[x]=v; } out[x]=++id, seq[id]=x; } void DFS2(int x,int tp) { top[x]=tp; if(son[x]) { DFS2(son[x],tp); for(int i=H[x]; i; i=nxt[i]) if(to[i]!=fa[x]&&to[i]!=son[x]) DFS2(to[i],to[i]); } } int Query_LCA(int x,int y) { while(top[x]!=top[y]) { if(dep[top[x]]<dep[top[y]]) std::swap(x,y); x=fa[top[x]]; } return dep[x]>dep[y]?y:x; } void Calc(int p) { if(vis[p]) if(!--tm[A[p]]) --Now; else ; else if(++tm[A[p]]==1) ++Now; vis[p]^=1; } int main() { // n=read(),m=read(); scanf("%d%d",&n,&m); Discrete(); // for(int u,v,i=1; i<n; ++i) u=read(),v=read(),AddEdge(u,v); for(int u,v,i=1; i<n; ++i) scanf("%d%d",&u,&v),AddEdge(u,v); Pre_DFS(1), DFS2(1,1); for(int u,v,w,i=1; i<=m; ++i) { // u=read(),v=read(),w=Query_LCA(u,v); scanf("%d%d",&u,&v),w=Query_LCA(u,v); q[i].id=i;//這要在continue前面。。 if(u==v) {q[i].lca=-1; continue;} if(in[u]>in[v]) std::swap(u,v); if(w==u) q[i].l=in[w],q[i].r=in[v],q[i].lca=0;//這部分的LCA不能和u=v時用一樣的! // else if(w==v) q[i].r=in[w],q[i].r=in[u],q[i].lca=0; else q[i].l=out[u],q[i].r=in[v],q[i].lca=in[w];//in[w] not w! } size=sqrt(id), std::sort(q+1,q+1+m); for(int l=1,r=0,i=1; i<=m; ++i) if(q[i].lca==-1) Ans[q[i].id]=1; else { while(l<q[i].l) Calc(seq[l++]); while(l>q[i].l) Calc(seq[--l]); while(r<q[i].r) Calc(seq[++r]); while(r>q[i].r) Calc(seq[r--]); if(q[i].lca) Calc(seq[q[i].lca]);//seq[in[lca]] not in[lca]! Ans[q[i].id]=Now; if(q[i].lca) Calc(seq[q[i].lca]); } for(int i=1; i<=m; ++i) printf("%d\n",Ans[i]); return 0; }

AC: 2.21s 8.5M

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

typedef long long ll;
const int N = 50010;
struct edge
{
    int to, next;
}g[N*2];
int n, m, unit;
struct node
{
    int l, r, anc, id;
    bool operator <(const node &b)const {return l/unit != b.l/unit ? l/unit < b.l/unit : r < b.r;}
}q[N*2];
int arr[N], ref[N];
int cnt, head[N];
int dep[N];
int in[N], out[N], seq[N*2], num;
int res[N*2], tmp, ver[N];
bool vis[N];
void add_edge(int v, int u)
{
    g[cnt].to = u, g[cnt].next = head[v], head[v] = cnt++;
}
void dfs(int v)
{
    in[v] = ++num;
    seq[num] = v;
    for(int i = head[v]; i != -1; i = g[i].next)
    {
        int u = g[i].to;
        if(! dep[u])
            dep[u] = dep[v] + 1, dfs(u);
    }
    out[v] = ++num;
    seq[num] = v;
}
namespace Subd
{
    int dep[N],fa[N],top[N],son[N],sz[N];
    void Pre_DFS(int x)
    {
        sz[x]=1;
        int mx=0;
        for(int v,i = head[x]; i != -1; i = g[i].next)
            if((v=g[i].to)!=fa[x])
            {
                fa[v]=x, dep[v]=dep[x]+1, Pre_DFS(v), sz[x]+=sz[v];
                if(sz[v]>mx) mx=sz[v],son[x]=v;
            }
    }
    void DFS2(int x,int tp)
    {
        top[x]=tp;
        if(son[x])
        {
            DFS2(son[x],tp);
            for(int v,i = head[x]; i != -1; i = g[i].next)
                if((v=g[i].to)!=fa[x]&&v!=son[x])
                    DFS2(v,v);
        }
    }
    int Query_LCA(int x,int y)
    {
        while(top[x]!=top[y])
        {
            if(dep[top[x]]<dep[top[y]]) std::swap(x,y);
            x=fa[top[x]];
        }
        return dep[x]>dep[y]?y:x;
    }
}
void Calc(int p)
{
    if(vis[p])
        if(!--ver[arr[p]]) --tmp;
        else ;
    else if(++ver[arr[p]]==1) ++tmp;
    vis[p]^=1;
}
int tot;
int Find(int x)
{
    int l=1,r=tot,mid;
    while(l<r)
        if(ref[mid=l+r>>1]>=x) r=mid;
        else l=mid+1;
    return l;
}
void Discrete()
{
    for(int i=1; i<=n; ++i) ref[i]=arr[i];
    sort(ref+1,ref+1+n);
    tot=1;
    for(int i=2; i<=n; ++i)
        if(ref[i]!=ref[i-1]) ref[++tot]=ref[i];
    for(int i=1; i<=n; ++i) arr[i]=Find(arr[i]);
}
//bool cmp(node a, node b){return a.l/unit != b.l/unit ? a.l/unit < b.l/unit : a.r < b.r;}

void solve()
{
    int a, b;
    for(int i = 1; i <= n; i++)
        scanf("%d", &arr[i]);
    Discrete();
    cnt = 0;
    memset(head, -1, sizeof head);
    for(int i = 1; i <= n - 1; i++) //存樹
        scanf("%d%d", &a, &b), add_edge(a, b), add_edge(b, a);
    memset(dep, 0, sizeof dep);
    dep[1] = 1;
    num = 0;
    dfs(1);
    Subd::Pre_DFS(1), Subd::DFS2(1,1);
    for(int u,v,i = 1; i <= m; i++)
    {
        scanf("%d%d", &u, &v);
        q[i].id = i;
        if(u == v) q[i].anc = -1; //特殊標記,此時公共祖先應該為1
        else
        {
            int w=Subd::Query_LCA(u,v);
            if(in[u]>in[v]) swap(u,v);
            if(w==u) q[i].l=in[w],q[i].r=in[v],q[i].anc=0;
            else q[i].l=out[u],q[i].r=in[v],q[i].anc=w;
        }
    }
    unit = sqrt(num);
    sort(q + 1, q + 1 + m);//分塊排序
    int l = 1, r = 0;
    tmp = 0;
    for(int i = 1; i <= m; i++)
        if(q[i].anc==-1) res[q[i].id]=1;
        else
        {
            while(l<q[i].l) Calc(seq[l++]);
            while(l>q[i].l) Calc(seq[--l]);
            while(r<q[i].r) Calc(seq[++r]);
            while(r>q[i].r) Calc(seq[r--]);
            if(q[i].anc>0) Calc(seq[in[q[i].anc]]);
            res[q[i].id]=tmp;
            if(q[i].anc>0) Calc(seq[in[q[i].anc]]);
        }
    for(int i = 1; i <= m; i++) printf("%d\n", res[i]);
}
int main()
{
    scanf("%d%d", &n, &m);
    solve();
    return 0;
}

SPOJ.COT2 Count on a tree II(樹上莫隊)