74 lines
1.8 KiB
C
74 lines
1.8 KiB
C
/**
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* File: binary_tree_bfs.c
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* Created Time: 2023-01-11
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* Author: Reanon (793584285@qq.com)
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*/
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#include "../utils/common.h"
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#define MAX_SIZE 100
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/* Level-order traversal */
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int *levelOrder(TreeNode *root, int *size) {
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/* Auxiliary queue */
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int front, rear;
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int index, *arr;
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TreeNode *node;
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TreeNode **queue;
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/* Auxiliary queue */
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queue = (TreeNode **)malloc(sizeof(TreeNode *) * MAX_SIZE);
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// Queue pointer
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front = 0, rear = 0;
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// Add root node
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queue[rear++] = root;
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// Initialize a list to store the traversal sequence
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/* Auxiliary array */
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arr = (int *)malloc(sizeof(int) * MAX_SIZE);
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// Array pointer
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index = 0;
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while (front < rear) {
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// Queue dequeues
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node = queue[front++];
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// Save node value
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arr[index++] = node->val;
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if (node->left != NULL) {
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// Left child node enqueues
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queue[rear++] = node->left;
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}
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if (node->right != NULL) {
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// Right child node enqueues
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queue[rear++] = node->right;
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}
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}
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// Update array length value
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*size = index;
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arr = realloc(arr, sizeof(int) * (*size));
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// Free auxiliary array space
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free(queue);
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return arr;
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}
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/* Driver Code */
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int main() {
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/* Initialize binary tree */
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// Use a specific function to convert an array into a binary tree
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int nums[] = {1, 2, 3, 4, 5, 6, 7};
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int size = sizeof(nums) / sizeof(int);
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TreeNode *root = arrayToTree(nums, size);
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printf("Initialize binary tree\n");
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printTree(root);
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/* Level-order traversal */
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// Required input array length
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int *arr = levelOrder(root, &size);
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printf("Sequence of nodes in level-order traversal = ");
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printArray(arr, size);
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// Free memory
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freeMemoryTree(root);
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free(arr);
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return 0;
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}
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