"BZOJ1095" [Zjoi2007]hide Hide-and-Seek "dynamic tree Partition" _ Divide and conquer

"Topic link"

Learn to delete a heap.

Find the center of gravity where forget to write!del[g[i].v],re countless hair.

/* Pigonometry/#include <cstdio> #include <cstring> #include <algorithm> #include <queue> usin

G namespace Std;

const int MAXN = 100005, MAXM = MAXN << 1, maxk =, inf = 0x3f3f3f3f;

int n, HEAD[MAXN], CNT;
int root, CLO, tot, bin[maxk], LG[MAXM];

int SIZE[MAXN], DEPTH[MAXN], SM[MAXN], PRE[MAXN], ST[MAXK][MAXM], DFN[MAXN], DEL[MAXN], COL[MAXN];

	struct _heap {priority_queue<int> A, B; void Update () {for (; B.size () && a.top () = = B.top ();
	A.pop (), B.pop ());
	void push (int x) {a.push (x);
		} void Pop () {update ();
	A.pop ();
	} void Erase (int x) {b.push (x);
	int size () {return a.size ()-b.size ();
		INT-I () {update (); Return A.size ()?
	A.top (): 0;
		int second () {if (Size () < 2) return 0; int x = i ();
		Pop (); int y = i ();
		push (x);
	return y;

} A, B[MAXN], C[MAXN];

struct _edge {int V, next;} G[MAXN << 1]; inline int iread () {int f = 1, x = 0; char ch = getchar (); for (; Ch < ' 0 ' | | | ch > ' 9 '; ch = getchar ()) F = ch = = '-'?
	-1:1;
	for (; Ch >= ' 0 ' && ch <= ' 9 '; ch = getchar ()) x = x * + ch-' 0 ';
return f * x;
	} inline void Add (int u, int v) {g[cnt] = (_edge) {V, head[u]};
Head[u] = cnt++;
	} inline void Dfs (int x, int f) {St[0][++clo] = depth[x];
	DFN[X] = CLO;
		for (int i = head[x]; ~i i = g[i].next) if (g[i].v ^ f) {depth[g[i].v] = depth[x] + 1;
		DFS (G[I].V, x);
	St[0][++clo] = depth[x];
	} inline int Getlca (int u, int v) {u = dfn[u]; v = dfn[v];
	if (U > v) swap (U, v);
	int t = lg[v-u + 1];
return min (St[t][u], st[t][v-bin[t] + 1]);

inline int dis (int u, int v) {return depth[u] + depth[v]-(GETLCA (U, v) << 1);}
	inline void Find (int x, int f) {size[x] = 1; sm[x] = 0;
		for (int i = head[x]; ~i i = g[i].next) if (g[i].v ^ f &&!del[g[i].v]) {Find (G[I].V, x);
		SIZE[X] + = SIZE[G[I].V];	
	SM[X] = max (sm[x], size[g[i].v]);	
	} Sm[x] = max (sm[x], tot-size[x]); if (Sm[x]< Sm[root]) root = x;
	} inline void Divide (int x, int f) {pre[x] = f; del[x] = 1;
		for (int i = head[x]; ~i i = g[i].next) if (g[i].v ^ f &&!del[g[i].v]) {root = 0; tot = size[g[i].v]; Find (G[I].V, x);
	Divide (root, x);
		} inline void turnoff (int x, int f) {if (x = = f) {b[x].push (0);
	if (b[x].size () = = 2) A.push (B[x].first ());

	} if (!pre[f]) return;
	int p = pre[f], d = dis (x, p), tmp = C[f].first ();

	C[f].push (d);
		if (d > tmp) {int mx = B[p].first () + B[p].second (), Sz = B[p].size ();
		B[p].push (d);
		if (TMP) b[p].erase (TMP);
		int now = B[p].first () + B[p].second ();
			if (now > mx) {if (SZ >= 2) a.erase (MX);
		if (B[p].size () >= 2) A.push (now);
} turnoff (x, p);
		} inline void Turnon (int x, int f) {if (x = = f) {if (b[x].size () = = 2) a.erase (B[x].first ());
	B[x].erase (0);

	} if (!pre[f]) return;
	int p = pre[f], d = dis (x, p), tmp = C[f].first ();

	C[f].erase (d); if (d = = tmp) {int mx = B[p].first () + B[p].second (), Sz = B[p].Size ();
		B[p].erase (d);
		if (C[f].first ()) B[p].push (C[f].first ());
		int now = B[p].first () + B[p].second ();
			if (now < MX) {if (SZ >= 2) a.erase (MX);
		if (B[p].size () >= 2) A.push (now);
} turnon (x, p);
	int main () {n = iread (); for (int i = 0; I <= N; i++) Head[i] =-1;

	CNT = 0;
	Bin[0] = 1;
	for (int i = 1; i < maxk i++) bin[i] = bin[i-1] << 1;
	Lg[0] =-1;


	for (int i = 1; i < MAXM i++) lg[i] = lg[i >> 1] + 1;
		for (int i = 1; i < n; i++) {int u = iread (), V = iread (); Add (U, v);
	Add (V, u);
	DFS (1, 0); for (int j = 1; j < Maxk; J +) for (int i = 1; I <= clo i++) if (i + bin[j]-1 <= clo) st[j][i] = min (st[j-1][

	I], st[j-1][i + bin[j-1]); Sm[0] = inf; root = 0;
	tot = n; Find (1, 0);

	Divide (root, 0);
	for (int i = 1; I <= n; i++) C[i].push (0), col[i] = 1;

	for (int i = 1; I <= n; i++) turnoff (i, I);
	int node = n; for (int T = Iread (); T t--) {Char ch = getchar (); for (; Ch!= ' C ' && ch!)= ' G ';
		ch = getchar ());
			if (ch = = ' G ') {if (node <= 1) printf ("%d\n", node-1);
		else printf ("%d\n", A.first ());
			else if (ch = = ' C ') {int u = iread ();
			if (col[u] = = 1) node--, turnon (U, u);
			else node++, turnoff (U, u);
		Col[u] ^= 1;
} return 0;
 }