[数据结构与算法]数据结构代码---二叉树的遍历

//
//   二叉树的遍历
//

# include<math.h>
# include<iostream>
# include<stdio.h>
using namespace std;

int num[30] = {1,2,4,0,0,5,0,0,3,6,0,0,7,0,0};
int i = 0;


typedef int Elemtype;

typedef struct BiTNode{     //链式存储结构
    Elemtype data;
    struct BiTNode *lchild,*rchild;
}BiTNode,*BiTree;

void visit(BiTree &T){
    printf("%d  ",T->data);
}

void preOrder(BiTree &T){
    if(T!=NULL){
        visit(T);
        preOrder(T->lchild);
        preOrder(T->rchild);
    }
}

void inOrder(BiTree &T){
    if(T!=NULL){
        inOrder(T->lchild);
        visit(T);
        inOrder(T->rchild);
    }
}

void postOrder(BiTree &T){
    if(T!=NULL){
        postOrder(T->lchild);
        postOrder(T->rchild);
        visit(T);
    }
}

void buildTree(BiTree &T){
    int el;
    el = num[i];i++;
//    scanf("%d",&el);
    if(el==0)
        T=NULL;
    else{
        T = (BiTNode *)malloc(sizeof(BiTNode));
        T->data = el;
        buildTree(T->lchild);
        buildTree(T->rchild);
    }

}

int main(void){
    BiTree T;
    T = NULL;
    buildTree(T);
    preOrder(T);
    printf("\n");
    inOrder(T);
    printf("\n");
    postOrder(T);
    printf("\n");
    return 0;
}