重建二叉树
#include<iostream> #define TREELEN 6 using namespace std;
struct Node { char chValue; Node* pLeft; Node* pRight; };
void ReBuild(char* pPreOrder,char* pInOrder,int nTreeLen,Node** pRoot) //重建二叉树 { if(pPreOrder==NULL || pInOrder==NULL)return ; Node* pTemp=new Node(); pTemp->chValue=*pPreOrder; pTemp->pLeft=NULL; pTemp->pRight=NULL; if(*pRoot==NULL) { *pRoot=pTemp; } if(nTreeLen==1)return; char* pOrgInOrder=pInOrder; char* pLeftEnd=pInOrder; int nTempLen=0; while(*pPreOrder!=*pLeftEnd) { if(pPreOrder==NULL || pLeftEnd==NULL)return; nTempLen++; if(nTempLen>nTreeLen)break; pLeftEnd++; } int nLeftLen=0;//寻找左子树长度 nLeftLen=(int)(pLeftEnd-pOrgInOrder); int nRightLen=0;//寻找右子树长度 nRightLen=nTreeLen-nLeftLen-1; //重建左子树 if(nLeftLen>0) { ReBuild(pPreOrder+1,pInOrder,nLeftLen,&((*pRoot)->pLeft)); } //重建右子树 if(nRightLen>0) { ReBuild(pPreOrder+nLeftLen+1,pInOrder+nLeftLen+1,nRightLen,&((*pRoot)->pRight)); } } void LastOrder(Node* pRoot) //后根遍历二叉树 { if(pRoot==NULL)return; LastOrder(pRoot->pLeft); LastOrder(pRoot->pRight); cout<<pRoot->chValue<<" "; } int main() { char szPreOrder[TREELEN]={'a','b','d','c','e','f'}; char szInOrder[TREELEN]={'d','b','a','e','c','f'}; Node* pRoot=NULL; ReBuild(szPreOrder,szInOrder,TREELEN,&pRoot); LastOrder(pRoot); cout<<endl; system("pause"); return 0; }
