對於資料結構初學者二叉樹是一個很好的練習題目,這裡記錄一下二叉樹的一些操作。
查詢二叉樹有一個特性
對於所有的節點,都滿足左子樹上的所有節點都比自己的小,而右子樹上的所有節點都比自己大
————《挑戰程式設計競賽第二版》P78
#include <iostream>
#include <stdlib.h>
using namespace std;
typedef struct TreeNode
{
int data;
struct TreeNode *LT, *RT;
}TreeNode, *TreeList;
//建立一個葉子節點
TreeNode* creatTree(int pData){
TreeNode *tree = (TreeNode*)malloc(sizeof(TreeNode));
tree->data = pData;
tree->LT = NULL;
tree->RT = NULL;
return tree;
}
int addLeaf(TreeList &node, int deep){
//傳參需要注意,二叉樹是指標型別的,節點本身就是一個指標:*node。所以需要二級指標才能改變二叉樹的內容
//TreeNode *node = NULL;
char input;
cin >> input;
if(input != '#'){
node = creatTree((int)input);
addLeaf(node->LT, deep + 1);
addLeaf(node->RT, deep + 1);
} else{
node = NULL;
}
return 1;
}
int treeInfo(TreeNode *tree, int deep){
cout << "deep: " << deep << ", data: " << (char)tree->data << endl;
if (tree->LT != NULL) treeInfo(tree->LT, deep + 1);
if (tree->RT != NULL) treeInfo(tree->RT, deep + 1);
return 0;
}
TreeNode *findValue(TreeNode *node, int value){
if (node == NULL) return NULL;
if (node->data == value) {
cout << "ok, find it." << endl;
return node;
}
else
return findValue(node->data < value ? node->RT : node->LT, value);
return NULL;
}
int main(){
char data;
TreeList tree, temp;
addLeaf(tree, 0);
cout << "start out info:" << endl;
treeInfo(tree, 0);
cout << "end out info" << endl;
cout << "input a num to find: ";
cin >> data;
temp = findValue(tree, data);
if (!temp) cout << "no find it." <<endl;
else cout << "find in " << &temp << ", data: " << (char)temp->data << endl;
}