linux學習總結（資料結構——樹、二叉樹以及遍曆）

二叉樹的儲存：

順序儲存浪費空間。

二叉樹鏈式儲存結構：

typedef int datatype;

typedef struct node{

　　datatype data;

struct node *lchild,*rchild;

}bitree,*root;

二叉樹的遍曆，由於二叉樹的遞迴性質，遍曆演算法也是遞迴的。三種基本的遍曆演算法如下：

先訪問樹根，再訪問左子樹，最後訪問右子樹  先根遍曆

先訪問左子樹，再訪問樹根，最後訪問右子樹 中根遍曆

先訪問左子樹，再訪問右子樹，最後訪問樹根 後根遍曆。

/*********************二叉樹***********************/#include <stdio.h>#include <stdlib.h>#define N  16typedef struct _node_{    int no;    struct _node_ *lchild, *rchild;}bitree;typedef bitree * datatype;typedef struct {    datatype data[N];    int front, rear;}sequeue;sequeue *CreateEmptySequeue(){    sequeue *sq;    sq = (sequeue*)malloc(sizeof(sequeue));    sq->front = sq->rear = 0;    return sq;}int EmptySequeue(sequeue *sq){    return sq->front == sq->rear;}void EnSequeue(sequeue *sq, datatype x){    sq->rear = (sq->rear + 1) % N;    sq->data[sq->rear] = x;    return;}datatype DeSequeue(sequeue *sq){    sq->front = (sq->front + 1)%N;    return sq->data[sq->front];}bitree *CreateBitree(int i, int n){    bitree *root;    root = (bitree *)malloc(sizeof(bitree));    root->no = i;    if(2*i <= n) root->lchild = CreateBitree(2*i, n);    else  root->lchild = NULL;    if(2*i+1 <= n) root->rchild = CreateBitree(2*i+1, n);    else root->rchild = NULL;    return root;}/***********遍曆*************/void PreOrder(bitree *root){    if(root == NULL)    return;    printf("%d ", root->no);    PreOrder(root->lchild);    PreOrder(root->rchild);    return;}void InOrder(bitree *root){    if(root == NULL)    return;    InOrder(root->lchild);    printf("%d ", root->no);    InOrder(root->rchild);    return;}void PostOrder(bitree *root){    if(root == NULL)    return;    PostOrder(root->lchild);    PostOrder(root->rchild);    printf("%d ", root->no);    return;}/***********按層次遍曆**************/void NoOrder(bitree *root){    sequeue *sq;    sq = CreateEmptySequeue();    EnSequeue(sq, root);    while(!EmptySequeue(sq))    {        root = DeSequeue(sq);        printf("%d ", root->no);        if(root->lchild != NULL)            EnSequeue(sq, root->lchild);        if(root->rchild != NULL)            EnSequeue(sq, root->rchild);    }    return;}int main(){    bitree *root;    root = CreateBitree(1, 10);        printf(" PreOrder:");    PreOrder(root);    printf("\n");    printf("  InOrder:");    InOrder(root);    printf("\n");    printf("PostOrder:");    PostOrder(root);    printf("\n");    printf("  NoOrder:");    NoOrder(root);    printf("\n");    return 0;}