剑指offer（六）

来源：互联网发布：淘宝默认付款是几天编辑：程序博客网时间：2024/06/06 03:07

1.反转链表

#include <iostream>using namespace std;struct List{int data;List* next;List(int num) :data(num),next(NULL){};};List* init_list(int *a,int n){List *head=new List(a[0]);List *q=head;for (int i=1;i<n;i++){List *p=new List(a[i]);q->next=p;q=p;}return head;}void reverse_list(List * &head)//注意点，要加引用{if(!head) return;//注意点List *p=head,*q,*r;if(head->next) q=head->next;if(head->next->next) r=head->next->next;p->next=NULL;while(r){q->next=p;if(r) ////注意点{p=q;q=r;}r=r->next;//注意点}q->next=p;head=q;}int main(){int a[]={0,1,2,3,4};int len=sizeof(a)/sizeof(a[0]);List *head=init_list(a,len);reverse_list(head);return 0;}

2.合并排序(递增)链表（结果还是递增的）

#include <iostream>using namespace std;struct List{int data;List* next;List(int num) :data(num),next(NULL){};};List* init_list(int *a,int n){List *head=new List(a[0]);List *q=head;for (int i=1;i<n;i++){List *p=new List(a[i]);q->next=p;q=p;}return head;}List* merge_sort_list(List * head1,List* head2){if (head1==NULL) return head2;else if (head2==NULL) return head1;List *temp=NULL;if(head1->data>head2->data){temp=head2;temp->next=merge_sort_list(head1,head2->next);}else{temp=head1;temp->next=merge_sort_list(head1->next,head2);}return temp;}int main(){int a[]={0,2};int b[]={1,3,5};int len=sizeof(a)/sizeof(a[0]);List *head1=init_list(a,len);List *head2=init_list(b,len+1);List *merge_list=merge_sort_list(head1,head2);return 0;}

3.判断是否是子树（两棵树A,B,判断是否B是A的子树）

#include <iostream>#include <vector>using namespace std;struct Btree{int data;Btree* left,*right;Btree(int num) :data(num),left(NULL),right(NULL){};};void  Find_The_root(Btree *A,Btree *B,int ×,Btree * &root){if(A&&B) {if (A->data==B->data)if (!times){root=A;times++;}Find_The_root(A->left,B,times,root);Find_The_root(A->right,B,times,root);}}bool Is_same(Btree * A,Btree *B){if(!B) return true;//返回条件if(!A||A->data!=B->data) return false;return(Is_same(A->left,B->left)&&Is_same(A->right,B->right));}void Is_child(Btree * A,Btree *B,bool &reslut){int times=0;Btree * temp_tree=NULL;Find_The_root(A,B,times,temp_tree);if(temp_tree){if(!Is_same(temp_tree,B)) {Is_child(temp_tree->left,B,reslut);Is_child(temp_tree->right,B,reslut);}else reslut=true;}}Btree* init_Btree(int *a,int n){vector<Btree *> v1;for (int i=0;i<n;i++){Btree * p=new Btree(a[i]);v1.push_back(p);}for (int i=0;i<=n/2-1;i++){v1[i]->left=v1[2*i+1];if(2*i+2<=n-1)v1[i]->right=v1[2*i+2];}return v1[0];}int main(){int a[]={2,2,3,4,5,6};int b[]={2,4,5};int len=sizeof(a)/sizeof(a[0]);Btree *A=init_Btree(a,len);len=sizeof(b)/sizeof(b[0]);Btree *B=init_Btree(b,len);bool result=false;Is_child(A,B,result);cout<<result;return 0;}

4.二叉树镜像

#include <iostream>#include <vector>using namespace std;struct Btree{int data;Btree* left,*right;Btree(int num) :data(num),left(NULL),right(NULL){};};void Mirror_Btree(Btree * &root){if(!root||(root->right==NULL&&root->left==NULL)) return ;Btree *temp=root->left;root->left=root->right;root->right=temp;Mirror_Btree(root->left);Mirror_Btree(root->right);}Btree* init_Btree(int *a,int n){vector<Btree *> v1;for (int i=0;i<n;i++){Btree * p=new Btree(a[i]);v1.push_back(p);}for (int i=0;i<=n/2-1;i++){v1[i]->left=v1[2*i+1];if(2*i+2<=n-1)v1[i]->right=v1[2*i+2];}return v1[0];}int main(){int a[]={1,2,3,4,5,6};int len=sizeof(a)/sizeof(a[0]);Btree *A=init_Btree(a,len);Mirror_Btree(A);return 0;}

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