hdu3966 Aragorn's Story【树链剖分+线段树】

来源：互联网发布：是知也的知的拼音编辑：程序博客网时间：2024/05/09 13:21
#pragma comment(linker,"/STACK:100000000,100000000")#include<bits/stdc++.h>using namespace std;const int N=50000+10;struct{    int f,l,r,sum;}tree[4*N];int g[N][2],c[N],top[N],fa[N],dep[N],son[N],sz[N],w[N],tot;vector<int>v[N];void dfs1(int x,int f){    int y,m=0;    dep[x]=dep[f]+1;    fa[x]=f;    sz[x]=1;    for(int i=0;i<v[x].size();i++)    {        y=v[x][i];        if(y==f) continue;        dfs1(y,x);        sz[x]+=sz[y];        if(m==0||sz[y]>sz[m])        {            m=y;            son[x]=y;        }    }}void dfs2(int x,int tp){    top[x]=tp;    w[x]=++tot;    if(son[x]==0) return ;    dfs2(son[x],tp);    for(int i=0;i<v[x].size();i++)    {        int y=v[x][i];        if(y==fa[x]||y==son[x]) continue;        dfs2(y,y);    }}void build(int o,int l,int r){    tree[o].l=l;    tree[o].r=r;    tree[o].f=0;    tree[o].sum=0;    if(l!=r)    {        int mid=(l+r)/2;        build(o*2,l,mid);        build(o*2+1,mid+1,r);    }}void pushdown(int o){    if(tree[o].l==tree[o].r) return ;    if(tree[o].f!=0)    {        tree[o*2].f+=tree[o].f;        tree[o*2+1].f+=tree[o].f;        tree[o*2].sum=tree[o*2].sum+(tree[o*2].r-tree[o*2].l+1)*tree[o].f;        tree[o*2+1].sum=tree[o*2+1].sum+(tree[o*2+1].r-tree[o*2+1].l+1)*tree[o].f;        tree[o].f=0;        tree[o].sum=tree[o*2].sum+tree[o*2+1].sum;    }}void update(int o,int k,int val){    if(k==tree[o].l&&tree[o].r==k)    {        tree[o].sum=val;        tree[o].f=0;    }    else    {        pushdown(o);        int mid=(tree[o].l+tree[o].r)/2;        if(k<=mid)  update(o*2,k,val);        else update(o*2+1,k,val);        tree[o].sum=tree[o*2].sum+tree[o*2+1].sum;    }}void update2(int o,int l,int r,int val){    if(l==tree[o].l&&tree[o].r==r)    {        pushdown(o);        tree[o].f=val;        tree[o].sum=tree[o].sum+(tree[o].r-tree[o].l+1)*val;    }    else    {        pushdown(o);        int mid=(tree[o].l+tree[o].r)/2;        if(r<=mid)  update2(o*2,l,r,val);        else if(l>mid) update2(o*2+1,l,r,val);        else        {            update2(o*2,l,mid,val);            update2(o*2+1,mid+1,r,val);        }        tree[o].sum=tree[o*2].sum+tree[o*2+1].sum;    }}int query(int o,int k){    if(k==tree[o].l&&tree[o].r==k)    {        return tree[o].sum;    }    else    {        pushdown(o);        int mid=(tree[o].l+tree[o].r)/2;        if(k<=mid)  query(o*2,k);        else query(o*2+1,k);    }}void change(int x,int y,int val){    int f1=top[x],f2=top[y];    while(f1!=f2)    {        if(dep[f1]<dep[f2])        {            swap(f1,f2);            swap(x,y);        }        update2(1,w[f1],w[x],val);        x=fa[f1];        f1=top[x];    }    if(dep[x]>dep[y]) swap(x,y);    update2(1,w[x],w[y],val);}int main(){    int n,m,p,a,b,t;    char s[10];    while(~scanf("%d%d%d",&n,&m,&p))    {        for(int i=1;i<=n;i++)            v[i].clear();        for(int i=1;i<=n;i++)        {            scanf("%d",&c[i]);        }        for(int i=1;i<n;i++)        {            scanf("%d%d",&g[i][0],&g[i][1]);            v[g[i][0]].push_back(g[i][1]);            v[g[i][1]].push_back(g[i][0]);        }        tot=0;        dep[0]=0;        memset(son,0,sizeof(son));        dfs1(1,0);        dfs2(1,1);        build(1,1,tot);        update(1,w[1],c[1]);        for(int i=1;i<n;i++)        {            if(dep[g[i][0]]>dep[g[i][1]])                swap(g[i][0],g[i][1]);            update(1,w[g[i][1]],c[g[i][1]]);        }        while(p--)        {            scanf("%s",s);            if(s[0]=='Q')            {                scanf("%d",&t);                printf("%d\n",query(1,w[t]));            }            else if(s[0]=='D')            {                scanf("%d%d%d",&a,&b,&t);                change(a,b,-t);            }            else if(s[0]=='I')            {                scanf("%d%d%d",&a,&b,&t);                change(a,b,t);            }        }    }    return 0;}
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