带翻转操作的LCT（LCT维护森林）（附BZOJ - 2049 洞穴勘测代码）

Link-Cut-Tree(with-Reverse).cpp

@@ -0,0 +1,164 @@
+#include <cstdio>
+
+#define NIL 0
+#define N 10010
+
+using namespace std;
+
+int n, m;
+int ch[N][2], fa[N], tf[N];
+bool rev[N];
+
+inline void swap(int *x)
+{
+	int temp = x[0];
+	x[0] = x[1];
+	x[1] = temp;
+}
+
+inline int which(int u)
+{
+	return ch[fa[u]][0] == u ? 0 : 1;
+}
+
+void rotate(int u)
+{
+	int p = fa[u];
+	int g = fa[p];
+	int k1 = which(u), k0 = which(p);
+	int c = ch[u][k1 ^ 1];
+	fa[c] = p;
+	fa[u] = g;
+	fa[p] = u;
+	ch[g][k0] = u;
+	ch[p][k1] = c;
+	ch[u][k1 ^ 1] = p;
+}
+
+void push_down(int u)
+{
+	if (rev[u] == true)
+	{
+		swap(ch[u]);
+		rev[u] = false;
+		rev[ch[u][0]] ^= true, rev[ch[u][1]] ^= true;
+	}
+}
+
+void splay(int u, int tar)
+{
+	static int path[N];
+	int pc = 0;
+	while (u != tar)
+	{
+		path[pc++] = u;
+		u = fa[u];
+	}
+	for (int i = pc - 1; i >= 0; i--)
+	{
+		push_down(path[i]);
+	}
+	u = path[0];
+	while (fa[u] != tar)
+	{
+		if (fa[fa[u]] != tar)
+		{
+			if (which(u) == which(fa[u])) rotate(fa[u]);
+			else rotate(u);
+		}
+		rotate(u);
+	}
+}
+
+int find_top(int u)
+{
+	push_down(u);
+	while (ch[u][0] != NIL)
+	{
+		u = ch[u][0];
+		push_down(u);
+	}
+	splay(u, NIL);
+	return u;
+}
+
+int get_root(int u)
+{
+	while (fa[u] != NIL)
+	{
+		u = fa[u];
+	}
+	return u;
+}
+
+void access(int u)
+{
+	int c = NIL;
+	while (u != NIL)
+	{
+		splay(u, NIL);
+		fa[ch[u][1]] = NIL;
+		if (ch[u][1] != NIL) tf[find_top(ch[u][1])] = u;
+		ch[u][1] = c;
+		fa[c] = u;
+		c = find_top(u);
+		u = tf[c];
+	}
+}
+
+void change_root(int u)
+{
+	access(u);
+	splay(u, NIL);
+	rev[u] = true;
+	find_top(u);
+	tf[u] = NIL;
+}
+
+void link(int u, int v)
+{
+	change_root(v);
+	tf[v] = u;
+}
+
+void cut(int u, int v)
+{
+	change_root(u);
+	access(v);
+	splay(u, NIL);
+	fa[v] = NIL;
+	ch[u][1] = NIL;
+	tf[v] = NIL;
+}
+
+bool query(int u, int v)
+{
+	change_root(u);
+	access(v);
+	if (get_root(u) == get_root(v)) return true;
+	else return false;
+}
+
+int main()
+{
+	char op[10];
+	int u, v;
+	scanf("%d%d", &n, &m);
+	while (m--)
+	{
+		scanf("%s%d%d", op, &u, &v);
+		if (op[0] == 'C')
+		{
+			link(u, v);
+		}
+		else if (op[0] == 'D')
+		{
+			cut(u, v);
+		}
+		else
+		{
+			printf("%s\n", query(u, v) == true ? "Yes" : "No");
+		}
+	}
+	return 0;
+}