113 lines
1.8 KiB
Java
113 lines
1.8 KiB
Java
public class BinarySearchTree {
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Node root;
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static class Node {
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int key;
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int value;
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Node l;
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Node r;
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Node p;
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public Node(int key, int value, Node p) {
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this.key = key;
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this.value = value;
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this.p = p;
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}
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}
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Node search(Node t, int key) {
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if (t == null || t.key == key)
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return t;
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if (key < t.key)
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return search(t.l, key);
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else
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return search(t.r, key);
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}
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public Node search(int key) {
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return search(root, key);
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}
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Node insert(Node t, Node p, int key, int value) {
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if (t == null) {
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t = new Node(key, value, p);
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} else {
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if (key < t.key)
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t.l = insert(t.l, t, key, value);
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else
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t.r = insert(t.r, t, key, value);
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}
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return t;
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}
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public void insert(int key, int value) {
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root = insert(root, null, key, value);
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}
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void replace(Node a, Node b) {
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if (a.p == null)
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root = b;
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else if (a == a.p.l)
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a.p.l = b;
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else
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a.p.r = b;
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if (b != null)
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b.p = a.p;
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}
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void remove(Node t, int key) {
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if (t == null)
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return;
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if (key < t.key)
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remove(t.l, key);
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else if (key > t.key)
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remove(t.r, key);
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else if (t.l != null && t.r != null) {
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Node m = t.r;
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while (m.l != null)
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m = m.l;
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t.key = m.key;
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t.value = m.value;
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replace(m, m.r);
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} else if (t.l != null) {
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replace(t, t.l);
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} else if (t.r != null) {
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replace(t, t.r);
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} else {
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replace(t, null);
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}
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}
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public void remove(int key) {
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remove(root, key);
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}
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void print(Node t) {
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if (t != null) {
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print(t.l);
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System.out.print(t.key + ":" + t.value + " ");
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print(t.r);
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}
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}
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public void print() {
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print(root);
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System.out.println();
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}
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// Usage example
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public static void main(String[] args) {
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BinarySearchTree tree = new BinarySearchTree();
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tree.insert(3, 1);
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tree.insert(2, 2);
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tree.insert(4, 5);
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tree.print();
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tree.remove(2);
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tree.remove(3);
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tree.print();
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tree.remove(4);
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}
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}
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