二叉树有关知识

// ConsoleApplication11.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <iostream>

using namespace std;

typedef struct TreeNode
{
int data;
struct TreeNode * pLeft;
struct TreeNode * pRight;
}TreeNode;
typedef struct TreeNode* pTreeNode;

void InOrder(pTreeNode p); //中序遍历

int _tmain(int argc, _TCHAR* argv[])
{

TreeNode *pRoot = new TreeNode;

TreeNode *temp1 = new TreeNode;
TreeNode *temp2 = new TreeNode;

pRoot->data = 1;
pRoot->pLeft = NULL;
pRoot->pRight = NULL;

temp1->data = 2;
temp1->pLeft = NULL;
temp1->pRight = NULL;
temp2->data = 3;
temp2->pLeft = NULL;
temp2->pRight = NULL;
pRoot->pLeft = temp1;
pRoot->pRight = temp2;
InOrder(pRoot);
return 0;
}

void InOrder(pTreeNode p)
{
if (p == NULL)
return;

InOrder(p->pLeft);
cout << p->data;
InOrder(p->pRight);
}

计算二叉树的宽度

// 获取最大宽度
    public static int getMaxWidth(TreeNode root) {
        if (root == null)
            return 0;

        Queue<TreeNode> queue = new ArrayDeque<TreeNode>();
        int maxWitdth = 1; // 最大宽度
        queue.add(root); // 入队

        while (true) {
            int len = queue.size(); // 当前层的节点个数
            if (len == 0)
                break;
            while (len > 0) {// 如果当前层，还有节点
                TreeNode t = queue.poll();
                len--;
                if (t.left != null)
                    queue.add(t.left); // 下一层节点入队
                if (t.right != null)
                    queue.add(t.right);// 下一层节点入队
            }
            maxWitdth = Math.max(maxWitdth, queue.size());
        }
        return maxWitdth;
    }