73 lines
1.7 KiB
C++
73 lines
1.7 KiB
C++
#include <iostream>
|
|
#include <vector>
|
|
|
|
class Node {
|
|
public:
|
|
int value;
|
|
Node* left;
|
|
Node* right;
|
|
|
|
// constructor to create a new node
|
|
Node(int val) : value(val), left(NULL), right(NULL) {}
|
|
};
|
|
|
|
// bfs using vectors
|
|
void breadth_first_traverse(Node* root) {
|
|
int level = 0;
|
|
std::vector<Node*> current_level;
|
|
std::vector<Node*> next_level;
|
|
|
|
if (root == NULL) {
|
|
return;
|
|
}
|
|
|
|
current_level.push_back(root);
|
|
|
|
while (current_level.size() != 0) {
|
|
std::cout << "level " << level << ":";
|
|
for (unsigned i = 0; i < current_level.size(); i++) {
|
|
if (current_level[i]->left != NULL) {
|
|
next_level.push_back(current_level[i]->left);
|
|
}
|
|
if (current_level[i]->right != NULL) {
|
|
next_level.push_back(current_level[i]->right);
|
|
}
|
|
std::cout << " " << current_level[i]->value;
|
|
}
|
|
current_level = next_level;
|
|
level++;
|
|
next_level.clear();
|
|
std::cout << std::endl;
|
|
}
|
|
}
|
|
|
|
int main() {
|
|
// creating a simple binary tree
|
|
// 1
|
|
// / \
|
|
// 2 3
|
|
// / \ / \
|
|
//4 5 6 7
|
|
Node* root = new Node(1);
|
|
root->left = new Node(2);
|
|
root->right = new Node(3);
|
|
root->left->left = new Node(4);
|
|
root->left->right = new Node(5);
|
|
root->right->left = new Node(6);
|
|
root->right->right = new Node(7);
|
|
|
|
// calling the breadth-first traversal function
|
|
breadth_first_traverse(root);
|
|
|
|
// cleaning up dynamically allocated memory
|
|
delete root->left->left;
|
|
delete root->left->right;
|
|
delete root->right->left;
|
|
delete root->right->right;
|
|
delete root->left;
|
|
delete root->right;
|
|
delete root;
|
|
|
|
return 0;
|
|
}
|