树链剖分
建树之后，安装软件就是让跟节点到安装的节点路径所有点权+1，卸载软件就是让一个节点和他的子数-1
要求变化数量的话直接求和相减就行啦（绝对值） 注意一点，一开始的lazyatag应该是-1，因为0代表pushdown所有节点应该变成0，1同理。#include#define INF 0x3f3f3f3f#define full(a, b) memset(a, b, sizeof a)using namespace std;typedef long long ll;inline int lowbit(int x){ return x & (-x); }inline int read(){ int X = 0, w = 0; char ch = 0; while(!isdigit(ch)) { w |= ch == '-'; ch = getchar(); } while(isdigit(ch)) X = (X << 3) + (X << 1) + (ch ^ 48), ch = getchar(); return w ? -X : X;}inline int gcd(int a, int b){ return a % b ? gcd(b, a % b) : b; }inline int lcm(int a, int b){ return a / gcd(a, b) * b; }template inline T max(T x, T y, T z){ return max(max(x, y), z); }template inline T min(T x, T y, T z){ return min(min(x, y), z); }template inline A fpow(A x, B p, C lyd){ A ans = 1; for(; p; p >>= 1, x = 1LL * x * x % lyd)if(p & 1)ans = 1LL * x * ans % lyd; return ans;}const int N = 100005;int n, cnt, dfn, head[N], size[N], depth[N], son[N], p[N], w[N], id[N], top[N];int tree[N<<2], lazy[N<<2];struct Edge { int v, next; } edge[N<<2];void addEdge(int a, int b){ edge[cnt].v = b, edge[cnt].next = head[a], head[a] = cnt ++;}void dfs1(int s, int fa){ depth[s] = depth[fa] + 1; p[s] = fa; size[s] = 1; int child = -1; for(int i = head[s]; i != -1; i = edge[i].next){ int u = edge[i].v; if(u == fa) continue; dfs1(u, s); size[s] += size[u]; if(size[u] > child) child = size[u], son[s] = u; }}void dfs2(int s, int tp){ id[s] = ++dfn; w[id[s]] = 0; top[s] = tp; if(son[s] != -1) dfs2(son[s], tp); for(int i = head[s]; i != -1; i = edge[i].next){ int u = edge[i].v; if(u == p[s] || u == son[s]) continue; dfs2(u, u); }}void push_up(int rt){ tree[rt] = tree[rt << 1] + tree[rt << 1 | 1];}void push_down(int rt, int l, int r){ if(lazy[rt] != -1){ int lson = rt << 1, rson = rt << 1 | 1, mid = (l + r) >> 1; lazy[lson] = lazy[rson] = lazy[rt]; tree[lson] = lazy[rt] * (mid - l + 1); tree[rson] = lazy[rt] * (r - mid); lazy[rt] = -1; }}void buildTree(int rt, int l, int r){ if(l == r){ tree[rt] = w[l]; return; } int mid = (l + r) >> 1; buildTree(rt << 1, l, mid); buildTree(rt << 1 | 1, mid + 1, r); push_up(rt);}void modify(int rt, int l, int r, int modifyL, int modifyR, int e){ if(l == modifyL && r == modifyR){ lazy[rt] = e; tree[rt] = (r - l + 1) * e; return; } push_down(rt, l, r); int mid = (l + r) >> 1; if(modifyL > mid) modify(rt << 1 | 1, mid + 1, r, modifyL, modifyR, e); else if(modifyR <= mid) modify(rt << 1, l, mid, modifyL, modifyR, e); else{ modify(rt << 1, l, mid, modifyL, mid, e); modify(rt << 1 | 1, mid + 1, r, mid + 1, modifyR, e); } push_up(rt);}int query(int rt, int l, int r, int queryL, int queryR){ if(l == queryL && r == queryR){ return tree[rt]; } push_down(rt, l, r); int mid = (l + r) >> 1; if(queryL > mid) return query(rt << 1 | 1, mid + 1, r, queryL, queryR); else if(queryR <= mid) return query(rt << 1, l, mid, queryL, queryR); else{ return query(rt << 1, l, mid, queryL, mid) + query(rt << 1 | 1, mid + 1, r, mid + 1, queryR); }}void treeModify(int x, int y, int e){ while(top[x] != top[y]){ if(depth[top[x]] < depth[top[y]]) swap(x, y); modify(1, 1, n, id[top[x]], id[x], e); x = p[top[x]]; } if(depth[x] > depth[y]) swap(x, y); modify(1, 1, n, id[x], id[y], e);}void sonModify(int x, int e){ modify(1, 1, n, id[x], id[x] + size[x] - 1, e);}int main(){ full(head, -1), full(lazy, -1), full(son, -1); n = read(); for(int i = 2; i <= n; i ++){ int u = read(); addEdge(u + 1, i), addEdge(i, u + 1); } dfs1(1, 0), dfs2(1, 1); buildTree(1, 1, n); int q = read(); while(q --){ char opt[20]; scanf("%s", opt); int x = read(), a = query(1, 1, n, 1, n); x ++; if(opt[0] == 'i'){ treeModify(1, x, 1); int b = query(1, 1, n, 1, n); printf("%d\n", abs(a - b)); } else if(opt[0] == 'u'){ sonModify(x, 0); int b = query(1, 1, n, 1, n); printf("%d\n", abs(a - b)); } } return 0;}