1086.Tree Traversals Again (25)...to be continued...

1086.Tree Traversals Again (25)…to be continued…

pat-al-1086

2017-02-1086

• 参考：《算法笔记：上机训练实战指南》机械工业出版社

/** * pat-al-1086 * 2017-02-18 * Cpp version * Author: fengLian_s */#include<stdio.h>#include<string.h>#include<stack>#define MAX 50using namespace std;int pre[MAX], in[MAX], post[MAX];struct NODE{  int data;  NODE* lchild;  NODE* rchild;};NODE* create(int preL, int preR, int inL, int inR){  if(preL > preR)    return NULL;  NODE* root = new NODE;  root->data = pre[preL];  int k;  for(k = inL;k <= inR;k++)  {    if(in[k] == pre[preL])      break;  }  int numLeft = k - inL;  root->lchild = create(preL+1, preL+numLeft, inL, k-1);  root->rchild = create(preL+numLeft+1, preR, k+1, inR);  return root;}int flagFirst = 1;void getPostOrder(NODE* root){  if(root == NULL)    return;  if(root->lchild != NULL)    getPostOrder(root->lchild);  if(root->rchild != NULL)    getPostOrder(root->rchild);  if(flagFirst == 1)  {    printf("%d", root->data);    flagFirst = 0;  }  else    printf(" %d", root->data);}int main(){  freopen("in.txt", "r", stdin);  int n;  scanf("%d", &n);  stack<int> st;  int cntPre = 0, cntIn;  for(int i = 0;i < 2*n;i++)//先把先序和中序提取出来  {    //printf("hello\n");    char oper[10];    scanf("%s", oper);    //printf("oper = %s\n", oper);    if(strcmp(oper, "Push") == 0)    {      //printf("hello, Push\n");      scanf("%d", &pre[cntPre]);      st.push(pre[cntPre++]);    }    else    {      in[cntIn++] = st.top();      //printf("%d ", in[cntIn-1]);      st.pop();    }  }  NODE* root = create(0, n-1, 0, n-1);  getPostOrder(root);  putchar('\n');  return 0;}

-TBC-