[luoguP2146] 软件包管理器（树链剖分）

传送门

看着很吓人，其实就是个树链剖分模板。

可支持操作：

1.将节点 x 到 根 的路径上的值都变成 1

2.将以节点 x 为根的子树的值都变成 0

1A爽~

——代码

 #include <cmath>
 #include <cstdio>
 #include <cstring>
 #include <iostream>
 #define root 1, 1, n
 #define ls now << 1, l, mid
 #define rs now << 1 | 1, mid + 1, r

 const int MAXN = ;
 int n, m, cnt, tim, ans;
 int head[MAXN], to[MAXN], next[MAXN];
 int f[MAXN], son[MAXN], size[MAXN], deep[MAXN], tid[MAXN], top[MAXN], sum[MAXN << ], turn[MAXN << ];

 inline int read()
 {
     int f = , x = ;
     char ch = getchar();
     for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = -;
     for(; isdigit(ch); ch = getchar()) x = (x << ) + (x << ) + ch - '';
     return x * f;
 }

 inline void add(int x, int y)
 {
     to[cnt] = y;
     next[cnt] = head[x];
     head[x] = cnt++;
 }

 inline void dfs1(int u)
 {
     int i, v;
     size[u] = ;
     deep[u] = deep[f[u]] + ;
     for(i = head[u]; i != -; i = next[i])
     {
         v = to[i];
         dfs1(v);
         size[u] += size[v];
         if(son[u] == - || size[son[u]] < size[v]) son[u] = v;
     }
 }

 inline void dfs2(int u, int tp)
 {
     int i, v;
     top[u] = tp;
     tid[u] = ++tim;
     if(son[u] != -) dfs2(son[u], tp);
     for(i = head[u]; i != -; i = next[i])
     {
         v = to[i];
         if(v != son[u]) dfs2(v, v);
     }
 }

 inline void swap(int &x, int &y)
 {
     x ^= y ^= x ^= y;
 }

 inline void pushup(int now)
 {
     sum[now] = sum[now << ] + sum[now <<  | ];
 }

 inline void pushdown(int now, int len)
 {
     if(turn[now] == -) return;
     sum[now << ] = turn[now] * (len - (len >> ));
     sum[now <<  | ] = turn[now] * (len >> );
     turn[now << ] = turn[now];
     turn[now <<  | ] = turn[now];
     turn[now] = -;
 }

 inline void update(int x, int ql, int qr, int now, int l, int r)
 {
     if(ql <= l && r <= qr)
     {
         ans += std::abs(x * (r - l + ) - sum[now]);
         sum[now] = (r - l + ) * x;
         turn[now] = x;
         return;
     }
     if(r < ql || l > qr) return;
     pushdown(now, r - l + );
     int mid = (l + r) >> ;
     update(x, ql, qr, ls);
     update(x, ql, qr, rs);
     pushup(now);
 }

 inline void qupdate(int x, int u, int v)
 {
     while(top[u] != top[v])
     {
         if(deep[top[u]] < deep[top[v]]) swap(u, v);
         update(x, tid[top[u]], tid[u], root);
         u = f[top[u]];
     }
     if(deep[u] > deep[v]) swap(u, v);
     update(x, tid[u], tid[v], root);
 }

 int main()
 {
     int i, x;
     char s[];
     n = read();
     memset(son, -, sizeof(son));
     memset(head, -, sizeof(head));
     memset(turn, -, sizeof(turn));
     for(i = ; i < n; i++)
     {
         x = read();
         f[i] = x;
         add(x, i);
     }
     dfs1();
     dfs2(, );
     m = read();
     for(i = ; i <= m; i++)
     {
         scanf("%s", s);
         x = read();
         ans = ;
         if(s[] == 'i') qupdate(, , x);
         else update(, tid[x], tid[x] + size[x] - , root);
         printf("%d\n", ans);
     }
     return ;
 }