P3261 [JLOI2015]城池攻占

P3261 [JLOI2015]城池攻占

乍一看，平衡树？

其实左偏树更好做啦\(qwq\)

每个节点都来棵左偏树维护最小值，\(dfs\)往上时合并一下，要是攻不下了就把根节点删掉，直到能攻下，
对了，攻下后值会变化怎么办？\(lazy\)标记一下，和线段树同理

**My complete code: **

#include<cstdio>
#include<iostream>
using namespace std;
typedef long long LL;
const LL maxn=400000;
struct node{
    LL to,next;
}dis[maxn];
struct code{
    LL val,lazy1,lazy2,dis;
    LL son[2];
}tree[maxn];
LL n,m,num; LL scc[maxn],dep[maxn],ans[maxn],belong[maxn],tmp[maxn],k[maxn],def[maxn],change[maxn];
LL head[maxn];
inline void add(LL u,LL v){
    dis[++num]=(node){v,head[u]}; head[u]=num;
}
inline void update(LL x){
    LL lazy1=tree[x].lazy1,
       lazy2=tree[x].lazy2,
       son0=tree[x].son[0],
       son1=tree[x].son[1];
    if(son0){
        tree[son0].val=tree[son0].val*lazy1+lazy2;
        tree[son0].lazy1*=lazy1;
        tree[son0].lazy2=tree[son0].lazy2*lazy1+lazy2;
    }
    if(son1){
        tree[son1].val=tree[son1].val*lazy1+lazy2;
        tree[son1].lazy1*=lazy1;
        tree[son1].lazy2=tree[son1].lazy2*lazy1+lazy2;
    }
    tree[x].lazy1=1;
    tree[x].lazy2=0;
}
LL merge(LL x,LL y){
    if(!x || !y)
        return x+y;
    update(x);
    update(y);
    if(tree[x].val>tree[y].val)
        swap(x,y);
    tree[x].son[1]=merge(tree[x].son[1],y);
    if(tree[tree[x].son[1]].dis>tree[tree[x].son[0]].dis)
        swap(tree[x].son[1],tree[x].son[0]);
    tree[x].dis=tree[tree[x].son[1]].dis+1;
    return x;
}
void dfs(LL u,LL fa){
    dep[u]=dep[fa]+1;
    for(LL i=head[u];i;i=dis[i].next){
        LL v=dis[i].to;
        dfs(v,u);
        if(!k[v]){
            tree[belong[v]].val+=change[v];
            tree[belong[v]].lazy2+=change[v];
        }else{
            tree[belong[v]].val*=change[v];
            tree[belong[v]].lazy1*=change[v];
            tree[belong[v]].lazy2*=change[v];
        }
        belong[u]=merge(belong[u],belong[v]);
    }
    while(belong[u] && tree[belong[u]].val<def[u]){
        ans[belong[u]]=u;
        scc[u]++;
        update(belong[u]);
        belong[u]=merge(tree[belong[u]].son[0],tree[belong[u]].son[1]);
    }
}
int main(){
    scanf("%lld%lld",&n,&m);
    for(LL i=1;i<=n;++i)
        scanf("%lld",def+i);
    for(LL i=2;i<=n;++i){
        LL u;
        scanf("%lld%lld%lld",&u,k+i,change+i);
        add(u,i);
    }
    for(LL i=1;i<=m;++i){
        scanf("%lld%lld",&tree[i].val,tmp+i);
        tree[i].lazy1=1;
        tree[i].lazy2=0;
        belong[tmp[i]]=merge(belong[tmp[i]],i);
    }
    dfs(1,0);
    for(LL i=1;i<=n;++i)
        printf("%lld\n",scc[i]);
    for(LL i=1;i<=m;++i)
        printf("%lld\n",dep[tmp[i]]-dep[ans[i]]);
    return 0;
}