java-algorithm-2010/boldTree/src/boldTree.java at master · xiaoningning/java-algorithm-2010 · GitHub

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import java.util.*;

public class boldTree {

private int number;

private boolean isBold;

private List<boldTree> children;

private boolean keep;

public boldTree(int n, boolean bold) {

number = n;

isBold = bold;

keep = true;

children = new ArrayList<boldTree>();

}

public static boldTree copy(boldTree node){

return new boldTree(node.number, node.isBold);

}

public void addChild(boldTree node) {

children.add(node);

}

public List<boldTree> getChildren() {

return children;

}

public boldTree getChild(int n) {

for (boldTree c : this.children) {

if (c.number == n)

return c;

}

return null;

}

public void removeChild(boldTree c) {

if (this.children.contains(c))

this.children.remove(c);

}

//the best, bottom-up by copying

public static boldTree boldSubTreeCopy(boldTree root) {

if (root == null)

return null;

boldTree tmp = copy(root);

for(boldTree c : root.getChildren()){

if(boldSubTreeCopy(c) != null){

tmp.addChild(c);

}

if(tmp.isBold ||tmp.getChildren().size() != 0)

return tmp;

else

return null;

}

// use flag, bottom-up

public static boldTree boldSubTree(boldTree root) {

if (root == null)

return null;

root.keep = root.isBold;

for(boldTree c : root.getChildren()){

if(boldSubTree(c).keep)

root.keep = true;

}

return root;

}

public static void show2(boldTree n) {

if (n == null){

System.out.println("no tree");

return;

}

Queue<boldTree> currentLevel = new LinkedList<boldTree>();

Queue<boldTree> nextLevel = new LinkedList<boldTree>();

currentLevel.add(n);

System.out.println(n.number + " ");

while (!currentLevel.isEmpty()) {

boldTree r = currentLevel.poll();

for (boldTree c : r.getChildren()) {

if (c.keep) {

if (c.isBold)

System.out.print(c.number + "(b) ");

else

System.out.print(c.number + " ");

}

nextLevel.add(c);

}

if (currentLevel.isEmpty()) {

currentLevel.addAll( nextLevel);

nextLevel.clear();

System.out.println();

}

// track non-bold node and remove, top-down approach

public static boldTree extractBoldSubTree(boldTree root) {

if (root == null) {

return null;

}

Queue<boldTree> currentLevel = new LinkedList<boldTree>();

Queue<boldTree> nextLevel = new LinkedList<boldTree>();

HashMap<boldTree, List<boldTree>> nonBoldNodeList = new HashMap<boldTree, List<boldTree>>();

currentLevel.add(root);

while (!currentLevel.isEmpty()) {

boldTree r = currentLevel.poll();

for (boldTree c : r.getChildren()) {

if (!hasBoldChild(c)) {

if (!nonBoldNodeList.containsKey(r))

nonBoldNodeList.put(r, new ArrayList<boldTree>());

nonBoldNodeList.get(r).add(c);

} else {

nextLevel.add(c);

}

if (currentLevel.isEmpty()) {

currentLevel.addAll(nextLevel);

nextLevel.clear();

for (boldTree k : nonBoldNodeList.keySet()) {

for (boldTree c : nonBoldNodeList.get(k)) {

k.removeChild(c);

}

nonBoldNodeList.clear();

}

return root;

}

public static boolean hasBoldChild(boldTree n) {

if(n == null)

return false;

for(boldTree c : n.getChildren()){

if(hasBoldChild(c))

return true;

}

return n.isBold;

}

public static void show(boldTree n) {

if (n == null){

System.out.println("no tree");

return;

}

Queue<boldTree> currentLevel = new LinkedList<boldTree>();

Queue<boldTree> nextLevel = new LinkedList<boldTree>();

currentLevel.add(n);

System.out.println(n.number + " ");

while (!currentLevel.isEmpty()) {

boldTree r = currentLevel.poll();

for (boldTree c : r.getChildren()) {

if (c.isBold)

System.out.print(c.number + "(b) ");

else

System.out.print(c.number + " ");

nextLevel.add(c);

}

if (currentLevel.isEmpty()) {

currentLevel = nextLevel;

nextLevel = new LinkedList<boldTree>();

System.out.println();

}

public static void main(String[] args) {

boldTree root = new boldTree(1, false);

boldTree c2 = new boldTree(2, false);

boldTree c3 = new boldTree(3, false);

boldTree c4 = new boldTree(4, true);

root.addChild(c2);

root.addChild(c3);

root.addChild(c4);

boldTree c22 = new boldTree(22, true);

c2.addChild(c22);

boldTree c31 = new boldTree(31, false);

boldTree c32 = new boldTree(32, true);

c3.addChild(c31);

c3.addChild(c32);

boldTree c41 = new boldTree(41, false);

boldTree c42 = new boldTree(42, false);

boldTree c43 = new boldTree(43, false);

c4.addChild(c41);

c4.addChild(c42);

c4.addChild(c43);

boldTree c221 = new boldTree(221, false);

c22.addChild(c221);

boldTree c311 = new boldTree(311, true);

c31.addChild(c311);

boldTree c421 = new boldTree(421, true);

boldTree c431 = new boldTree(431, false);

c42.addChild(c421);

c43.addChild(c431);

boldTree root2 = root;

System.out.println("source tree");

show(root);

System.out.println("bold tree");

boldTree newRoot = extractBoldSubTree(root);

show(newRoot);

// need a flag to keep if the node should be included.

System.out.println("another way to extract bold tree");

boldTree newRoot2 = boldSubTree(root2);

show2(newRoot2);

System.out.println("another way to extract bold tree by copying: ");

boldTree newRoot3 = boldSubTreeCopy(root2);

show(newRoot3);

}

java-algorithm-2010/boldTree/src/boldTree.java at master · xiaoningning/java-algorithm-2010 · GitHub

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