将一棵二叉树的全部节点的左右子树交换顺序

模拟了层次遍历的算法。

#include<iostream>#include<malloc.h>#include<queue>#include<list>using namespace std;struct node{char c;node *lchild,*rchild;};char pre[100];char mid[100];void build(node* &t,int start1,int end1,int start2,int end2){int i=start2;while(pre[start1]!=mid[i])i=i+1;t=(node*)malloc(sizeof(node));t->c=pre[start1];if(i==start2)t->lchild=NULL;else build(t->lchild,start1+1,start1+i-start2,start2,i-1);if(i==end2)t->rchild=NULL;else build(t->rchild,start1+i-start2+1,end1,i+1,end2);}list<node*> que;list<node*> temp;void exchange(node *t){if(!temp.empty())temp.clear();temp.push_back(t);while(!temp.empty()){node* q;q=temp.front();if(q->lchild)temp.push_back(q->lchild);if(q->rchild)temp.push_back(q->rchild);temp.pop_front();node *r;r=q->lchild;q->lchild=q->rchild;q->rchild=r;}}void visit(node *t){if(!que.empty())que.clear();que.push_back(t);while(!que.empty()){node *x;x=que.front();cout<<x->c;que.pop_front();if(x->lchild)que.push_back(x->lchild);if(x->rchild)que.push_back(x->rchild);}}int main(){node *tree;int length;while(1==1){cout<<"pre"<<endl;cin>>pre;cout<<"mid"<<endl;cin>>mid;length=strlen(mid);build(tree,0,length-1,0,length-1);exchange(tree);visit(tree);}return 0;}