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Copy pathLinkCutTree.java
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213 lines (185 loc) · 4.67 KB
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import java.util.*;
public class LinkCutTre {
static class Node {
Node left, right, parent;
boolean rev;
long val;
long sum;
int id;
Node(int id, long val) {
this.id = id;
this.val = val;
this.sum = val;
}
}
private final Node[] nodes;
public LinkCutTree(int n) {
nodes = new Node[n + 1];
for (int i = 1; i <= n; i++) {
nodes[i] = new Node(i, 0);
}
}
private void pull(Node x) {
x.sum = x.val + (x.left != null ? x.left.sum : 0) + (x.right != null ? x.right.sum : 0);
}
private void push(Node x) {
if (x == null) {
return;
}
if (x.rev) {
Node t = x.left;
x.left = x.right;
x.right = t;
if (x.left != null) {
x.left.rev ^= true;
}
if (x.right != null) {
x.right.rev ^= true;
}
x.rev = false;
}
}
private boolean isSplayRoot(Node x) {
Node p = x.parent;
return p == null || (p.left != x && p.right != x);
}
private void rotate(Node x) {
Node p = x.parent;
Node g = p.parent;
if (!isSplayRoot(p)) {
if (g.left == p) {
g.left = x;
}else {
g.right = x;
}
}
x.parent = g;
if (p.left == x) {
p.left = x.right;
if (x.right != null) {
x.right.parent = p;
}
x.right = p;
p.parent = x;
} else {
p.right = x.left;
if (x.left != null) {
x.left.parent = p;
}
x.left = p;
p.parent = x;
}
pull(p);
pull(x);
}
private void pushPath(Node x) {
if (!isSplayRoot(x)) {
pushPath(x.parent);
}
push(x);
}
private void splay(Node x) {
if (x == null) {
return;
}
pushPath(x);
while (!isSplayRoot(x)) {
Node p = x.parent;
Node g = p.parent;
if (!isSplayRoot(p)) {
if ((p.left == x) == (g.left == p)) {
rotate(p);
}else {
rotate(x);
}
}
rotate(x);
}
}
private Node access(Node x) {
Node last = null;
for (Node y = x; y != null; y = y.parent) {
splay(y);
y.right = last;
pull(y);
last = y;
}
splay(x);
return last;
}
private void makeRoot(Node x) {
access(x);
x.rev ^= true;
push(x);
}
private Node findRoot(Node x) {
access(x);
while (true) {
push(x);
if (x.left == null) {
break;
}
x = x.left;
}
splay(x);
return x;
}
public boolean link(int ui, int vi) {
Node u = nodes[ui], v = nodes[vi];
makeRoot(u);
if (findRoot(v) == u) {
return false;
}
u.parent = v;
return true;
}
public boolean cut(int ui, int vi) {
Node u = nodes[ui], v = nodes[vi];
makeRoot(u);
access(v);
if (v.left == u && u.right == null) {
v.left.parent = null;
v.left = null;
pull(v);
return true;
}
return false;
}
public boolean connected(int ui, int vi) {
return findRoot(nodes[ui]) == findRoot(nodes[vi]);
}
public void update(int ui, long newVal) {
Node u = nodes[ui];
access(u);
u.val = newVal;
pull(u);
}
public long query(int ui, int vi) {
Node u = nodes[ui], v = nodes[vi];
makeRoot(u);
access(v);
return v.sum;
}
public static void main(String[] args) {
LinkCutTree lct = new LinkCutTree(7);
for (int i = 1; i <= 7; i++) {
lct.update(i, i);
}
lct.link(1, 2);
lct.link(2, 3);
lct.link(3, 4);
lct.link(5, 6);
lct.link(6, 7);
System.out.println(lct.connected(1, 4));
System.out.println(lct.query(1, 4));
System.out.println(lct.connected(1, 5));
lct.link(4, 5);
System.out.println(lct.connected(1, 7));
System.out.println(lct.query(2, 7));
lct.cut(3, 4);
System.out.println(lct.connected(1, 7));
System.out.println(lct.query(1, 3));
lct.update(2, 20);
System.out.println(lct.query(1, 3));
}
}