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
1 #include <cmath> 2 #include <cstdio> 3 #include <cstring> 4 #include <iostream> 5 #define root 1, 1, n 6 #define ls now << 1, l, mid 7 #define rs now << 1 | 1, mid + 1, r 8 9 const int MAXN = 1000001; 10 int n, m, cnt, tim, ans; 11 int head[MAXN], to[MAXN], next[MAXN]; 12 int f[MAXN], son[MAXN], size[MAXN], deep[MAXN], tid[MAXN], top[MAXN], sum[MAXN << 2], turn[MAXN << 2]; 13 14 inline int read() 15 { 16 int f = 1, x = 0; 17 char ch = getchar(); 18 for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = -1; 19 for(; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + ch - '0'; 20 return x * f; 21 } 22 23 inline void add(int x, int y) 24 { 25 to[cnt] = y; 26 next[cnt] = head[x]; 27 head[x] = cnt++; 28 } 29 30 inline void dfs1(int u) 31 { 32 int i, v; 33 size[u] = 1; 34 deep[u] = deep[f[u]] + 1; 35 for(i = head[u]; i != -1; i = next[i]) 36 { 37 v = to[i]; 38 dfs1(v); 39 size[u] += size[v]; 40 if(son[u] == -1 || size[son[u]] < size[v]) son[u] = v; 41 } 42 } 43 44 inline void dfs2(int u, int tp) 45 { 46 int i, v; 47 top[u] = tp; 48 tid[u] = ++tim; 49 if(son[u] != -1) dfs2(son[u], tp); 50 for(i = head[u]; i != -1; i = next[i]) 51 { 52 v = to[i]; 53 if(v != son[u]) dfs2(v, v); 54 } 55 } 56 57 inline void swap(int &x, int &y) 58 { 59 x ^= y ^= x ^= y; 60 } 61 62 inline void pushup(int now) 63 { 64 sum[now] = sum[now << 1] + sum[now << 1 | 1]; 65 } 66 67 inline void pushdown(int now, int len) 68 { 69 if(turn[now] == -1) return; 70 sum[now << 1] = turn[now] * (len - (len >> 1)); 71 sum[now << 1 | 1] = turn[now] * (len >> 1); 72 turn[now << 1] = turn[now]; 73 turn[now << 1 | 1] = turn[now]; 74 turn[now] = -1; 75 } 76 77 inline void update(int x, int ql, int qr, int now, int l, int r) 78 { 79 if(ql <= l && r <= qr) 80 { 81 ans += std::abs(x * (r - l + 1) - sum[now]); 82 sum[now] = (r - l + 1) * x; 83 turn[now] = x; 84 return; 85 } 86 if(r < ql || l > qr) return; 87 pushdown(now, r - l + 1); 88 int mid = (l + r) >> 1; 89 update(x, ql, qr, ls); 90 update(x, ql, qr, rs); 91 pushup(now); 92 } 93 94 inline void qupdate(int x, int u, int v) 95 { 96 while(top[u] != top[v]) 97 { 98 if(deep[top[u]] < deep[top[v]]) swap(u, v); 99 update(x, tid[top[u]], tid[u], root); 100 u = f[top[u]]; 101 } 102 if(deep[u] > deep[v]) swap(u, v); 103 update(x, tid[u], tid[v], root); 104 } 105 106 int main() 107 { 108 int i, x; 109 char s[10]; 110 n = read(); 111 memset(son, -1, sizeof(son)); 112 memset(head, -1, sizeof(head)); 113 memset(turn, -1, sizeof(turn)); 114 for(i = 1; i < n; i++) 115 { 116 x = read(); 117 f[i] = x; 118 add(x, i); 119 } 120 dfs1(0); 121 dfs2(0, 0); 122 m = read(); 123 for(i = 1; i <= m; i++) 124 { 125 scanf("%s", s); 126 x = read(); 127 ans = 0; 128 if(s[0] == 'i') qupdate(1, 0, x); 129 else update(0, tid[x], tid[x] + size[x] - 1, root); 130 printf("%d ", ans); 131 } 132 return 0; 133 }