[BZOJ2836]魔法树（链剖+dfs序）

来源：互联网发布：godaddy 域名续费编辑：程序博客网时间：2024/04/28 15:22

题目描述

传送门

题解

链剖+dfs序裸题。
强转又搞错了？

代码

#include<iostream>#include<cstring>#include<cstdio>using namespace std;#define LL long longconst int max_n=1e5+5;const int max_tree=max_n*4;const int max_m=max_n;LL n,m,x,y,q,u,t,d,N; LL ans;LL tot,point[max_n],nxt[max_m],v[max_m];LL size[max_n],h[max_n],father[max_n],top[max_n],in[max_n],out[max_n],son[max_n];LL sum[max_tree],delta[max_tree];char opt[20];inline void addedge(LL x,LL y){    ++tot; nxt[tot]=point[x]; point[x]=tot; v[tot]=y;}inline void dfs_1(LL x,LL fa,LL dep){    size[x]=1; h[x]=dep; father[x]=fa;    LL maxson=0;    for (LL i=point[x];i;i=nxt[i])        if (v[i]!=fa)        {            dfs_1(v[i],x,dep+1);            size[x]+=size[v[i]];            if (size[v[i]]>maxson)            {                maxson=size[v[i]];                son[x]=v[i];            }        }}inline void dfs_2(LL x,LL fa){    if (son[fa]!=x) top[x]=x;    else top[x]=top[fa];    in[x]=++N;    if (son[x]) dfs_2(son[x],x);    for (LL i=point[x];i;i=nxt[i])        if (v[i]!=fa&&v[i]!=son[x])            dfs_2(v[i],x);    out[x]=N;}inline void update(LL now){    sum[now]=sum[now<<1]+sum[now<<1|1];}inline void pushdown(LL now,LL l,LL r,LL mid){    if (delta[now])    {        sum[now<<1]+=delta[now]*(LL)(mid-l+1);        delta[now<<1]+=delta[now];        sum[now<<1|1]+=delta[now]*(LL)(r-mid);        delta[now<<1|1]+=delta[now];        delta[now]=0;    }}inline void interval_change(LL now,LL l,LL r,LL lrange,LL rrange,LL v){    LL mid=(l+r)>>1;    if (lrange<=l&&r<=rrange)    {        sum[now]+=v*(LL)(r-l+1);        delta[now]+=v;        return;    }    pushdown(now,l,r,mid);    if (lrange<=mid) interval_change(now<<1,l,mid,lrange,rrange,v);    if (mid+1<=rrange) interval_change(now<<1|1,mid+1,r,lrange,rrange,v);    update(now);}inline LL query(LL now,LL l,LL r,LL lrange,LL rrange){    LL mid=(l+r)>>1;LL ans=0;    if (lrange<=l&&r<=rrange) return sum[now];    pushdown(now,l,r,mid);    if (lrange<=mid) ans+=query(now<<1,l,mid,lrange,rrange);    if (mid+1<=rrange) ans+=query(now<<1|1,mid+1,r,lrange,rrange);    return ans;}int main(){    scanf("%lld",&n);    for (LL i=1;i<n;++i)    {        scanf("%lld%lld",&x,&y);        x++; y++;        addedge(x,y);    }    dfs_1(1,0,1);    dfs_2(1,0);    scanf("%lld",&q);    for (LL i=1;i<=q;++i)    {        scanf("%s",opt);        if (opt[0]=='A')        {            scanf("%lld%lld%lld",&u,&t,&d);            ++u; ++t;            LL f1=top[u],f2=top[t];            while (f1!=f2)            {                if (h[f1]<h[f2])                {                    swap(f1,f2);                    swap(u,t);                }                interval_change(1,1,N,in[f1],in[u],d);                u=father[f1];                f1=top[u];            }            if (in[u]>in[t]) swap(u,t);            interval_change(1,1,N,in[u],in[t],d);        }        else        {            scanf("%lld",&u);            ++u;            ans=query(1,1,N,in[u],out[u]);            printf("%lld\n",ans);        }    }}

手工栈

#include<iostream>#include<cstring>#include<cstdio>using namespace std;#define LL long longconst int max_n=1e5+5;const int max_tree=max_n*4;const int max_m=max_n;LL n,m,x,y,q,u,t,d,N; LL ans;LL tot,point[max_n],nxt[max_m],v[max_m];LL size[max_n],h[max_n],father[max_n],top[max_n],in[max_n],out[max_n],son[max_n];LL sum[max_tree],delta[max_tree];char opt[20];int stack[max_n],cur[max_n];bool use[max_n];inline void addedge(LL x,LL y){    ++tot; nxt[tot]=point[x]; point[x]=tot; v[tot]=y;}void dfs_1(){    int tmp=0;    stack[++tmp]=1;h[1]=1;size[1]=1LL;    for (int i=1;i<=n;++i) cur[i]=point[i];    while (tmp)    {        int x=stack[tmp];        if (cur[x]&&father[x]==v[cur[x]]) cur[x]=nxt[cur[x]];        if (!cur[x])        {            --tmp;            if (father[x])            {                size[father[x]]+=size[x];                if (size[son[father[x]]]<size[x]) son[father[x]]=x;            }            continue;        }        int vt=v[cur[x]];        stack[++tmp]=vt;        size[vt]=1LL;h[vt]=h[x]+1;father[vt]=x;        cur[x]=nxt[cur[x]];    }}void dfs_2(){    int tmp=0;    stack[++tmp]=1;top[1]=1;in[1]=++N;    for (int i=1;i<=n;++i) cur[i]=point[i];    while (tmp)    {        int x=stack[tmp];        if (!use[x])        {            use[x]=1;            int vt=son[x];            if (vt)            {                stack[++tmp]=vt;                in[vt]=++N;                top[vt]=top[x];            }            continue;        }        while (cur[x]&&(father[x]==v[cur[x]]||son[x]==v[cur[x]])) cur[x]=nxt[cur[x]];        if (!cur[x])        {            int vt=stack[tmp--];            out[vt]=N;        }        else        {            int vt=v[cur[x]];            stack[++tmp]=vt;            in[vt]=++N;            top[vt]=vt;            cur[x]=nxt[cur[x]];        }    }}inline void update(LL now){    sum[now]=sum[now<<1]+sum[now<<1|1];}inline void pushdown(LL now,LL l,LL r,LL mid){    if (delta[now])    {        sum[now<<1]+=delta[now]*(LL)(mid-l+1);        delta[now<<1]+=delta[now];        sum[now<<1|1]+=delta[now]*(LL)(r-mid);        delta[now<<1|1]+=delta[now];        delta[now]=0;    }}inline void interval_change(LL now,LL l,LL r,LL lrange,LL rrange,LL v){    LL mid=(l+r)>>1;    if (lrange<=l&&r<=rrange)    {        sum[now]+=v*(LL)(r-l+1);        delta[now]+=v;        return;    }    pushdown(now,l,r,mid);    if (lrange<=mid) interval_change(now<<1,l,mid,lrange,rrange,v);    if (mid+1<=rrange) interval_change(now<<1|1,mid+1,r,lrange,rrange,v);    update(now);}inline LL query(LL now,LL l,LL r,LL lrange,LL rrange){    LL mid=(l+r)>>1;LL ans=0;    if (lrange<=l&&r<=rrange) return sum[now];    pushdown(now,l,r,mid);    if (lrange<=mid) ans+=query(now<<1,l,mid,lrange,rrange);    if (mid+1<=rrange) ans+=query(now<<1|1,mid+1,r,lrange,rrange);    return ans;}int main(){    scanf("%lld",&n);    for (LL i=1;i<n;++i)    {        scanf("%lld%lld",&x,&y);        x++; y++;        addedge(x,y);    }    dfs_1();    dfs_2();    scanf("%lld",&q);    for (LL i=1;i<=q;++i)    {        scanf("%s",opt);        if (opt[0]=='A')        {            scanf("%lld%lld%lld",&u,&t,&d);            ++u; ++t;            LL f1=top[u],f2=top[t];            while (f1!=f2)            {                if (h[f1]<h[f2])                {                    swap(f1,f2);                    swap(u,t);                }                interval_change(1,1,N,in[f1],in[u],d);                u=father[f1];                f1=top[u];            }            if (in[u]>in[t]) swap(u,t);            interval_change(1,1,N,in[u],in[t],d);        }        else        {            scanf("%lld",&u);            ++u;            ans=query(1,1,N,in[u],out[u]);            printf("%lld\n",ans);        }    }}

0 0