我正在开发一个图形SFML BST菜单系统。我有测试文件。其中一些给出了预期的输出,但其他的没有。我一直想弄清楚几天,我不明白为什么。这些数字似乎正确地插入到树中,但是具有重复数字的输入似乎打破了树遍历的结构,因为并非所有节点都将被输出。请参阅下面的代码和示例。
我的.h文件中有一个strut等等,我确信它可以正常工作。
有谁可以告诉我为什么其中一些不会遍历所有节点?
输入:1,3,5,6,7,8,9,10 输出:图表看起来像预期的那样,遍历看起来像预期的那样。
输入:3,4,99,3,10,11,10 产出3,3,10,10(不预期)
输入:10,3,10,24,3,20 产出:3,3,10,10,24
//Binary Search Tree Program
#include "BinarySearchTree.h"
using namespace std;
sf::CircleShape shape(50);
BinarySearchTree::BinarySearchTree()
{
root = NULL;
if (!font.loadFromFile("font.ttf"))
cout << "Error loading font!";
}
void BinarySearchTree::loadFile(int num) {
data.clear();
string s = to_string(num);
string text;
string temp; // Added this line
ifstream file;
file.open("files/file" + s + ".txt");
while (!file.eof())
{
getline(file, temp);
text.append(temp); // Added this line
}
std::istringstream ss(text);
std::string token;
while (std::getline(ss, token, ',')) {
std::cout << token << ',';
std::string myString = token;
int value = atoi(myString.c_str()); //value = 45
data.push_back(value);
}
}
void BinarySearchTree::passToinsert()
{
for (std::vector<int>::iterator it = data.begin(); it != data.end(); ++it) {
insert(*it);
//cout << *it;
}
}
void BinarySearchTree::insert(int d)
{
tree_node* t = new tree_node;
tree_node* parent;
t->data = d;
t->left = NULL;
t->right = NULL;
parent = NULL;
// is this a new tree?
if (isEmpty()) root = t;
else
{
//Note: ALL insertions are as leaf nodes
tree_node* curr;
curr = root;
// Find the Node's parent
while (curr)
{
parent = curr;
if (t->data > curr->data) curr = curr->right;
else curr = curr->left;
}
if (t->data < parent->data) {
parent->left = t;
cout << "L-" << t->data<<endl;
}
else {
parent->right = t;
cout << "R-" << t->data << endl;
}
}
}
void BinarySearchTree::print_inorder()
{
inorder(root);
}
void BinarySearchTree::inorder(tree_node* p)
{
if (p != NULL)
{
if (p->left) inorder(p->left);
cout << " " << p->data << " ";
if (p->right) inorder(p->right);
}
else return;
}
void BinarySearchTree::print_postorder()
{
postorder(root, 100,0,0,0,0);
}
void BinarySearchTree::postorder(tree_node* p, int indent, int leftNodeCount, int rightNodeCount, int left, int right)
{
if (p != NULL) {
if (left = 1) {
std::string s = std::to_string(p->data);
nodes[nodeCount].setFont(font);
nodes[nodeCount].setFillColor(sf::Color::White);
nodes[nodeCount].setString(s);
nodes[nodeCount].setPosition(sf::Vector2f(indent, 80 + (leftNodeCount * 80)));
nodeCount++;
leftNodeCount++;
}
else if (right = 1) {
std::string s = std::to_string(p->data);
nodes[nodeCount].setFont(font);
nodes[nodeCount].setFillColor(sf::Color::White);
nodes[nodeCount].setString(s);
nodes[nodeCount].setPosition(sf::Vector2f(indent, 80 + (rightNodeCount * 80)));
nodeCount++;
rightNodeCount++;
}
else {
std::string s = std::to_string(p->data);
nodes[nodeCount].setFont(font);
nodes[nodeCount].setFillColor(sf::Color::White);
nodes[nodeCount].setString(s);
nodes[nodeCount].setPosition(sf::Vector2f(indent, 80 + (nodeCount * 80)));
nodeCount++;
}
if (p->right) {
postorder(p->right, indent + 80, leftNodeCount, rightNodeCount,left=0,right=1);
}
if (p->left) {
postorder(p->left, indent - 80, leftNodeCount, rightNodeCount, left = 1, right = 0);
}
}
}
//Draw sub menu heading text and options to screen
void BinarySearchTree::drawNodes(sf::RenderWindow &window)
{
window.clear();
for (int i = 0; i < 10; i++)
{
window.draw(nodes[i]);
}
window.display();
}
答案 0 :(得分:0)
实际上,数字没有正确插入树中。主要问题位于insert()
的{{1}}函数。
在while循环class BinarySearchTree
中,左侧和右侧之间的切换由if条件while (curr)
管理,假设案例if (t->data > curr->data)
连接到左侧。
在while循环之后,左侧和右侧之间的切换由if条件t->data == curr->data
管理,假设案例if (t->data < parent->data)
连接到右侧。 而不是左侧!!!
解决方案 - 只需在while循环中交换开关条件,如下所示。
t->data == parent->data
而不是:
if (t->data < curr->data) {
curr = curr->left;
}
else {
curr = curr->right;
}