題解

連樹剖我都寫跪一次，我現在怎麽那麽老年啊= =
簡直滾粗預定了啊。。

我們線段樹維護樹剖只需要資瓷區間覆蓋和區間求和就好了
安裝的時候看看自己到根有多少包裝了，dep減去這個數量就好
卸載的時候看看子樹裏有多少包安裝了就行

代碼

#include <bits/stdc++.h>
//#define ivorysi
#define enter putchar(‘\n‘)
#define space putchar(‘ ‘)
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define eps 1e-8
 

#define mo 974711
#define MAXN 100005
#define pii pair<int,int>
using namespace std;
typedef long long int64;
typedef double db;
template<class T>
void read(T &res) {
    res = 0;char c = getchar();T f = 1;
    while(c < ‘0‘ || c > ‘9‘) {
    if(c == ‘-‘) f = -1;
    c = getchar();
    }
    while
 
(c >= ‘0‘ && c <= ‘9‘) {
    res = res * 10 + c - ‘0‘;
    c = getchar();
    }
    res *= f;
}
template<class T>
void out(T x) {
    if(x < 0) {putchar(‘-‘);x = -x;}
    if(x >= 10) {
    out(x / 10);
    }
    putchar(‘0‘ + x % 10);
}

struct node {
    int to,next;
}E[MAXN * 2];
struct
 
 Tr_node {
    int L,R;
    int sum,cover;
}tr[MAXN * 4];
int head[MAXN],sumE,N,Q;
int dep[MAXN],fa[MAXN],siz[MAXN],son[MAXN];
int dfn[MAXN],idx,top[MAXN],L[MAXN];
void add_cover(int u,int v) {
    if(v == 1) {
    tr[u].sum = tr[u].R - tr[u].L + 1;
    tr[u].cover = 1;
    }
    else {
    tr[u].sum = 0;
    tr[u].cover = -1;
    }
}
void push_down(int u) {
    if(tr[u].cover) {
    add_cover(u << 1,tr[u].cover);
    add_cover(u << 1 | 1,tr[u].cover);
    tr[u].cover = 0;
    }
}
void update(int u) {
    tr[u].sum = tr[u << 1].sum + tr[u << 1 | 1].sum;
}
void add(int u,int v) {
    E[++sumE].to = v;
    E[sumE].next = head[u];
    head[u] = sumE;
}
void dfs1(int u) {
    dep[u] = dep[fa[u]] + 1;
    siz[u] = 1;
    for(int i = head[u] ; i ; i = E[i].next) {
    int v = E[i].to;
    if(v != fa[u]) {
        fa[v] = u;
        dfs1(v);
        siz[u] += siz[v];
        if(siz[v] > siz[son[u]]) son[u] = v;
    }
    }
}
void dfs2(int u) {
    dfn[u] = ++idx;
    L[idx] = u;
    if(!top[u]) top[u] = u;
    if(son[u]) {
    top[son[u]] = top[u];
    dfs2(son[u]);
    }
    for(int i = head[u] ; i ; i = E[i].next) {
    int v = E[i].to;
    if(v != fa[u] && v != son[u]) dfs2(v);
    }
}
void build(int u,int l,int r) {
    tr[u].L = l;tr[u].R = r;
    tr[u].cover = tr[u].sum = 0;
    if(l == r) return;
    int mid = (l + r) >> 1;
    build(u << 1,l,mid);
    build(u << 1 | 1,mid + 1,r);
}
int Query(int u,int l,int r) {
    if(tr[u].L == l && tr[u].R == r) return tr[u].sum;
    push_down(u);
    int mid = (tr[u].L + tr[u].R) >> 1;
    if(r <= mid) Query(u << 1,l,r);
    else if(l > mid) Query(u << 1 | 1,l,r);
    else return Query(u << 1,l,mid) + Query(u << 1 | 1,mid + 1,r);
}
void Cover(int u,int l,int r,int v) {
    if(tr[u].L == l && tr[u].R == r) {
    add_cover(u,v);
    return;
    }
    push_down(u);
    int mid = (tr[u].L + tr[u].R) >> 1;
    if(r <= mid) Cover(u << 1,l,r,v);
    else if(l > mid) Cover(u << 1 | 1,l,r,v);
    else Cover(u << 1,l,mid,v),Cover(u << 1 | 1,mid + 1,r,v);
    update(u);
}

void Change(int u,int v) {
    while(u) {
    Cover(1,dfn[top[u]],dfn[u],v);
    u = fa[top[u]];
    }
}
int Query_Tr(int u) {
    int res = 0;
    while(u) {
    res += Query(1,dfn[top[u]],dfn[u]);
    u = fa[top[u]];
    }
    return res;
}
void Solve() {
    read(N);
    int p;
    for(int i = 2 ; i <= N ; ++i) {
    read(p);++p;add(i,p);add(p,i);
    }
    dfs1(1);dfs2(1);
    build(1,1,N);
    read(Q);
    char s[20];
    for(int i = 1 ; i <= Q ; ++i) {
    scanf("%s",s + 1);read(p);
    ++p;
    if(s[1] == ‘i‘) {
        out(dep[p] - Query_Tr(p));
        Change(p,1);
    }
    else {
        out(Query(1,dfn[p],dfn[p] + siz[p] - 1));
        Cover(1,dfn[p],dfn[p] + siz[p] - 1,-1);
    }
    enter;
    }
}
int main() {
#ifdef ivorysi
    freopen("f1.in","r",stdin);
#endif
    Solve();
    return 0;
}

【LOJ】 #2130. 「NOI2015」軟件包管理器