bzoj 3531（树链剖分）

传送门

每个宗教维护一棵线段树，要动态开点，否则可能会爆空间，数组到底开多少本蒟蒻也不清楚，反正稍微开大点，对于此题的空间如果动态开还是可以稍微多开一点的，其余的就是链剖模板了。
注意：在update时不仅要更新线段树，原来的数组a[],c[]（宗教、评级）也要修改！

#include<bits/stdc++.h>#define lson lc[rt],l,mid#define rson rc[rt],mid+1,rusing namespace std;const int maxn=1e5+2,MN=5e6+2;int n,m,a[maxn],c[maxn];int head[maxn],edge=0,tim=0;struct EDGE {    int v,nxt;}e[maxn<<1];int mx[MN],sum[MN],lc[MN],rc[MN],root[maxn];int fa[maxn],dep[maxn],siz[maxn],top[maxn],rk[maxn],tid[maxn],son[maxn];inline int read() {    int x=0;char c=getchar();    while (c<'0'||c>'9') c=getchar();    while (c>='0'&&c<='9') x=x*10+c-'0',c=getchar();    return x;}inline void adde(int u,int v) {    e[edge].v=v,e[edge].nxt=head[u],head[u]=edge++;    e[edge].v=u,e[edge].nxt=head[v],head[v]=edge++;}void dfs1(int p,int father) {    fa[p]=father,dep[p]=dep[fa[p]]+1,siz[p]=1;    for (int i=head[p];~i;i=e[i].nxt) {        int v=e[i].v;        if (v==fa[p]) continue;        dfs1(v,p);        siz[p]+=siz[v];        if (son[p]==-1||siz[son[p]]<siz[v])            son[p]=v;    }}void dfs2(int p,int tp) {    top[p]=tp,tid[p]=++tim,rk[tid[p]]=p;    if (son[p]==-1) return ;    dfs2(son[p],tp);    for (int i=head[p];~i;i=e[i].nxt) {        int v=e[i].v;        if (v!=fa[p]&&v!=son[p])            dfs2(v,v);    }}inline void pushup(int rt) {    mx[rt]=max(mx[lc[rt]],mx[rc[rt]]);    sum[rt]=sum[lc[rt]]+sum[rc[rt]];}void update(int &rt,int l,int r,int pos,int val) {    if (!rt) rt=++tim;    if (l==r) {        mx[rt]=sum[rt]=val;        return ;    }    int mid=(l+r)>>1;    if (pos<=mid) update(lson,pos,val);    else update(rson,pos,val);    pushup(rt);}int qsum(int rt,int l,int r,int L,int R) {    if (L<=l&&r<=R) return sum[rt];    int mid=(l+r)>>1,ans=0;    if (L<=mid) ans+=qsum(lson,L,R);    if (mid<R) ans+=qsum(rson,L,R);    return ans;}int qmax(int rt,int l,int r,int L,int R) {    if (L<=l&&r<=R) return mx[rt];    int mid=(l+r)>>1,ans=0;    if (L<=mid) ans=max(ans,qmax(lson,L,R));    if (mid<R) ans=max(ans,qmax(rson,L,R));    return ans;}int get_sum(int x,int y) {    int res=0,cc=c[x];    while (top[x]^top[y]) {        if (dep[top[x]]<dep[top[y]]) x^=y^=x^=y;        res+=qsum(root[cc],1,n,tid[top[x]],tid[x]);        x=fa[top[x]];    }    if (dep[x]>dep[y]) x^=y^=x^=y;    res+=qsum(root[cc],1,n,tid[x],tid[y]);    return res;}int get_max(int x,int y) {    int res=0,cc=c[x];    while (top[x]^top[y]) {        if (dep[top[x]]<dep[top[y]]) x^=y^=x^=y;        res=max(res,qmax(root[cc],1,n,tid[top[x]],tid[x]));        x=fa[top[x]];    }    if (dep[x]>dep[y]) x^=y^=x^=y;    res=max(res,qmax(root[cc],1,n,tid[x],tid[y]));    return res;}int main() {//  freopen("bzoj 3531.in","r",stdin);    memset(mx,0,sizeof(mx)),    memset(sum,0,sizeof(sum)),    memset(root,0,sizeof(root)),    memset(lc,0,sizeof(lc)),    memset(rc,0,sizeof(rc)),    memset(head,-1,sizeof(head)),    memset(son,-1,sizeof(son)),    n=read(),m=read();    for (register int i=1;i<=n;++i)        a[i]=read(),c[i]=read();    for (register int i=1;i<n;++i) {        int u=read(),v=read();        adde(u,v);    }    dfs1(1,1);    dfs2(1,1),tim=0;//tim would be used again in the segtree    for (register int i=1;i<=n;++i)        update(root[c[i]],1,n,tid[i],a[i]);    while (m--) {        char ss[5];        scanf("%s",ss);        if (!strcmp(ss,"CC")) {            int pos=read(),val=read();            update(root[c[pos]],1,n,tid[pos],0);            c[pos]=val;            update(root[c[pos]],1,n,tid[pos],a[pos]);        }        else if (!strcmp(ss,"CW")) {            int pos=read(),val=read();            update(root[c[pos]],1,n,tid[pos],a[pos]=val);        }        else if (!strcmp(ss,"QS")) {            int s=read(),t=read();            printf("%d\n",get_sum(s,t));        }        else {            int s=read(),t=read();            printf("%d\n",get_max(s,t));        }    }    return 0;}