76 lines
1.9 KiB
C
76 lines
1.9 KiB
C
/**
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* File: binary_tree_dfs.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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// Auxiliary array for storing traversal sequence
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int arr[MAX_SIZE];
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/* Pre-order traversal */
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void preOrder(TreeNode *root, int *size) {
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if (root == NULL)
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return;
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// Visit priority: root node -> left subtree -> right subtree
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arr[(*size)++] = root->val;
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preOrder(root->left, size);
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preOrder(root->right, size);
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}
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/* In-order traversal */
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void inOrder(TreeNode *root, int *size) {
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if (root == NULL)
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return;
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// Visit priority: left subtree -> root node -> right subtree
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inOrder(root->left, size);
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arr[(*size)++] = root->val;
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inOrder(root->right, size);
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}
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/* Post-order traversal */
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void postOrder(TreeNode *root, int *size) {
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if (root == NULL)
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return;
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// Visit priority: left subtree -> right subtree -> root node
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postOrder(root->left, size);
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postOrder(root->right, size);
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arr[(*size)++] = root->val;
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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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/* Pre-order traversal */
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// Initialize auxiliary array
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size = 0;
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preOrder(root, &size);
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printf("Sequence of nodes in pre-order traversal = ");
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printArray(arr, size);
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/* In-order traversal */
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size = 0;
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inOrder(root, &size);
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printf("Sequence of nodes in in-order traversal = ");
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printArray(arr, size);
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/* Post-order traversal */
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size = 0;
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postOrder(root, &size);
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printf("Sequence of nodes in post-order traversal = ");
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printArray(arr, size);
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freeMemoryTree(root);
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return 0;
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}
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