思路就是下载的话找 0 的个数,然后把 x 到根的链上的都设为 1,卸载就输出子树中 1 的个数,然后把子树给变 0。
#include <vector>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int maxn = 1e5 + 10;
char s[10];
struct node {
int l, r, sum, add;
} t[maxn << 2];
vector<int> G[maxn];
int n, m, op, x, TIME, d[maxn], f[maxn], dfn[maxn], top[maxn], siz[maxn], son[maxn];
void df(int u, int fa) {
d[u] = d[fa] + 1;
f[u] = fa;
siz[u] = 1;
for (auto v : G[u]) {
if (v == fa) continue;
df(v, u);
siz[u] += siz[v];
if (siz[son[u]] < siz[v]) son[u] = v;
}
return ;
}
void dfs(int u, int x) {
dfn[u] = ++TIME;
top[u] = x;
if (son[u]) dfs(son[u], x);
for (auto v : G[u]) {
if (v == f[u] || v == son[u]) continue;
dfs(v, v);
}
return ;
}
void push_up(int u) {
t[u].sum = t[u << 1].sum + t[u << 1 | 1].sum;
return ;
}
void tag(int u, int v) {
t[u].sum = (t[u].r - t[u].l + 1) * v;
t[u].add = v;
return ;
}
void push_down(int u) {
tag(u << 1, t[u].add);
tag(u << 1 | 1, t[u].add);
t[u].add = 0;
return ;
}
void build(int u, int l, int r) {
t[u].l = l;
t[u].r = r;
t[u].add = 0;
if (l == r) {
t[u].sum = 0;
return ;
}
int mid = l + r >> 1;
build(u << 1, l, mid);
build(u << 1 | 1, mid + 1, r);
push_up(u);
return ;
}
void update(int u, int x, int y, int k) {
if (t[u].l >= x && t[u].r <= y) {
tag(u, k);
return ;
}
push_down(u);
int mid = t[u].l + t[u].r >> 1;
if (x <= mid) update(u << 1, x, y, k);
if (y > mid) update(u << 1 | 1, x, y, k);
push_up(u);
return ;
}
int query(int u, int x, int y) {
if (x <= t[u].l && t[u].r <= y) return t[u].sum;
int res = 0;
int mid = t[u].l + t[u].r >> 1;
push_down(u);
if (x <= mid) res += query(u << 1, x, y);
if (y > mid) res += query(u << 1 | 1, x, y);
return res;
}
void upd(int x, int y, int k) {
while (top[x] ^ top[y]) {
if (d[top[x]] < d[top[y]]) swap(x, y);
update(1, dfn[top[x]], dfn[x], k);
x = f[top[x]];
}
if (d[x] > d[y]) swap(x, y);
update(1, dfn[x], dfn[y], k);
return ;
}
int qr(int x, int y) {
int ans = 0;
while (top[x] ^ top[y]) {
if (d[top[x]] < d[top[y]]) swap(x, y);
ans += (dfn[x] - dfn[top[x]] + 1) - query(1, dfn[top[x]], dfn[x]);
x = f[top[x]];
}
if (d[x] > d[y]) swap(x, y);
ans += (dfn[y] - dfn[x] + 1) * query(1, dfn[x], dfn[y]);
return ans;
}
int main() {
scanf("%d", &n);
for (int i = 1; i < n; i++) {
scanf("%d", &x);
G[i].push_back(x);
G[x].push_back(i);
}
df(0, 0);
dfs(0, 0);
build(1, 0, n - 1);
scanf("%d", &m);
while (m--) {
scanf(" %s %d", s, &x);
if (s[0] == 'i') {
printf("%d\n", qr(1, x));
upd(1, x, 1);
} else {
printf("%d\n", query(1, dfn[x], dfn[x] + siz[x] - 1));
update(1, dfn[x], dfn[x] + siz[x] - 1, 0);
}
}
return 0;
}