9.2 1020 Tree Traversals (25 分)（***）

#include <cstdio>
#include <queue>
using namespace std;
struct node
{
    int data;
    node* lc;
    node* rc;
};
int n,pos[100],in[100];

node* creat(int pl,int pr,int il,int ir)
{
    if(pl > pr)
        return NULL;
    node* root = new node;
    root->data = pos[pr];
    int temp = root->data;
    int i;
    for(i = il;i<=ir;i++)
    {
        if(in[i] == pos[pr])
        {
            break;
        }
    }
    int numl = ir - i;

    root->lc = creat(pl,pr - numl - 1,il,i-1);
    root->rc = creat(pr - numl,pr - 1,i+1,ir);

    return root;
}

void proT(node*root)
{
    if(root == NULL)
        return;
    printf("%d ",root->data);
    proT(root->lc);
    proT(root->rc);
}
void levelT(node*root)
{
    int flag = 0;
    queue<node*>q;
    q.push(root);
    while(!q.empty())
    {
        node* s = q.front();
        q.pop();
        if(flag == 0)
        {
            printf("%d",s->data);
            flag = 1;
        }
        else
        {
            printf(" %d",s->data);
        }

        if(s->lc != NULL)
        {
            q.push(s->lc);
        }

        if(s->rc != NULL)
        {
            q.push(s->rc);
        }

    }
}

int main()
{

    freopen("in.txt","r",stdin);
    scanf("%d",&n);
   for(int i = 1;i<=n;i++)
   {
       scanf("%d",&pos[i]);
   }
   for(int i = 1;i<=n;i++)
   {
       scanf("%d",&in[i]);
   }
   levelT(creat(1,n,1,n));


    return 0;
}