1020. Tree Traversals (25) PAT甲级

来源：互联网发布：淘宝教育官网编辑：程序博客网时间：2024/05/17 00:55
传送门
#include<stdio.h>#include<queue>using namespace std;#define MAX_N 37int inorder[MAX_N],postorder[MAX_N];typedef struct Node{    int data;    Node *lchild,*rchild;}node,*Btree;void create(Btree &bt,int posL,int posR,int inL,int inR){    if(posL>posR){        bt=NULL;        return;    }    bt=new node;    bt->data=postorder[posR];    int leftnum;    int i;    for(i=inL;i<=inR;i++){        if(inorder[i]==postorder[posR]){            leftnum=i-inL;            break;        }    }    create(bt->lchild,posL,posL+leftnum-1,inL,i-1);    create(bt->rchild,posL+leftnum,posR-1,i+1,inR);}void preorder(Btree root){    if(root==NULL)        return ;    else{        preorder(root->lchild);        printf("%d ",root->data);        preorder(root->rchild);    }}void level(Btree root,int n){    queue<Btree> q;    int count=0;    q.push(root);    while(!q.empty()){        Btree bt=q.front();        q.pop();        printf("%d",bt->data);        count++;        if(count<n) printf(" ");        if((bt->lchild)!=NULL)  {q.push(bt->lchild);}        if((bt->rchild)!=NULL)  {q.push(bt->rchild);}    }}int main(){    int n;    scanf("%d",&n);    for(int i=0;i<n;i++){        scanf("%d",&postorder[i]);    }    for(int i=0;i<n;i++){        scanf("%d",&inorder[i]);    }    Btree root=NULL;    create(root,0,n-1,0,n-1);    level(root,n);    //preorder(root);}
0 0