题解 | #二叉排序树#

#include<iostream>
#include<cstring>
using namespace std;
int arr[101];
typedef struct BiTNode {
    int data;
    struct BiTNode* L, * R;
}BiTNode, * BiTree;
void Insert_Bitree(BiTree & root, int k) {
    if (root == NULL) {
        root = (BiTNode*)malloc(sizeof(BiTNode));
        root->data = k;
        root->L = NULL;
        root->R = NULL;

    }
    else if (root->data == k) {
        return;

    }
    else if (root->data > k) {
        Insert_Bitree(root->L, k);
    }
    else {
        Insert_Bitree(root->R, k);
    }

}
void Pre_Order(BiTree& T) {
    if (T != NULL) {
        cout << T->data << " ";
        Pre_Order(T->L);
        Pre_Order(T->R);

    }
    return;

}
void In_Order(BiTree& T) {
    if (T != NULL) {  
        In_Order(T->L);
        cout << T->data << " ";
        In_Order(T->R);

    }
    return;

}
void Post_Order(BiTree& T) {
    if (T != NULL) {     
        Post_Order(T->L);
        Post_Order(T->R);
        cout << T->data << " ";

    }
    return;
}

int main() {
    int n;
    while (cin >> n && n) {
        memset(arr, 0, 101);
        for (int i = 0; i < n; i++) {
            cin >> arr[i];
        }
        BiTree T=NULL;

        for (int i = 0; i < n; i++) {
            Insert_Bitree(T, arr[i]);
        }
        Pre_Order(T);
        cout << endl;
        In_Order(T);
        cout<<endl;
        Post_Order(T);
        cout<<endl;



    }



}