1.理論
1.1 二叉樹
每個節點最多隻有兩個子節點的樹1.2 滿二叉樹
所有的葉子節點都在最後一層,並且節點總數 2^n-1 n 爲層數
1.3 完全二叉樹
所有的葉子節點都在最後一層或者倒數第二層,而且最後一層的葉子節點在左邊連續,倒數第二層的葉子節點在右邊連續2.代碼
2.1 思路分析
前序:先輸出父節點,再遍歷左子樹和右子樹
中序:先遍歷左子樹,再輸出父節點,再遍歷右子樹
後序:先遍歷左子樹,再遍歷右子樹,最後輸出父節點
2.2 代碼樣例
class BinaryTree {
private HeroNode root;
public void setRoot(HeroNode root) {
this.root = root;
}
//前序遍歷
public void preOrder() {
if (this.root != null) {
this.root.preOrder();
}
}
public void infixOrder() {
if (this.root != null) {
this.root.infixOrder();
}
}
public void postOrder() {
if (this.root != null) {
this.root.postOrder();
}
}
}
class HeroNode {
private int no;
private String name;
private HeroNode left;
private HeroNode right;
public HeroNode(int no, String name) {
this.no = no;
this.name = name;
}
public int getNo() {
return no;
}
public void setNo(int no) {
this.no = no;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public HeroNode getLeft() {
return left;
}
public void setLeft(HeroNode left) {
this.left = left;
}
public HeroNode getRight() {
return right;
}
public void setRight(HeroNode right) {
this.right = right;
}
@Override
public String toString() {
return "HearNode{" +
"no=" + no +
", name='" + name + '\'' +
'}';
}
//前序遍歷
public void preOrder() {
System.out.println(this);
if (this.left != null) {
this.left.preOrder();
}
if (this.right != null) {
this.right.preOrder();
}
}
//中序遍歷
public void infixOrder() {
if (this.left != null) {
this.left.infixOrder();
}
System.out.println(this);
if (this.right != null) {
this.right.infixOrder();
}
}
//後序遍歷
public void postOrder() {
if (this.left != null) {
this.left.postOrder();
}
if (this.right != null) {
this.right.postOrder();
}
System.out.println(this);
}
}