二叉搜索树的习题 pta

今天鸡血打完了，直接贴代码就不解释了

根据后序和中序遍历输出先序遍历

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#include <iostream>
#include <algorithm>
#include <stdio.h>
#include <string.h>
#define MAXINT  32767
using namespace std;
struct BtreeNode{
    int data;
    struct BtreeNode* left;
    struct BtreeNode* right;
};
typedef struct BtreeNode* node;
typedef struct BtreeNode btree;
int hou[35],in[35],n;
node creat(int *hou,int *in,int n){
    int root,i;
    if(n==-1)return NULL;
    root=hou[n];
    node t;
    t=new btree;
    t->data=root;
    for(i=0;i<=n;i++)
        if(in[i]==root)
            break;
    t->left=creat(hou,in,i-1);
    t->right=creat(hou+i,in+i+1,n-i-1);
    return t;
}
void qianxu(node tt){
    if(tt){
        cout<<" "<<tt->data;
        qianxu(tt->left);
        qianxu(tt->right);
    }
}
int main()
{
    node tt;
    int i;
    cin>>n;
    for(i=0;i<n;i++)
        cin>>hou[i];
    for(i=0;i<n;i++)
        cin>>in[i];
    tt=creat(hou,in,n-1);
    cout<<"Preorder:";
    qianxu(tt);
    cout<<endl;
    return 0;
}

是否同一棵二叉搜索树
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#include <iostream>
#include <stdio.h>
#include <string.h>
using namespace std;
struct BtreeNode{
    int data;
    struct BtreeNode *left;
    struct BtreeNode *right;
};
typedef struct BtreeNode* node;
typedef struct BtreeNode btree;
node creat(node t,int n){
    int m,i;
    node p,q,s;
    for(i=0;i<n;i++){
    cin>>m;
    s=new btree;
    s->data=m;  s->left=NULL;  s->right=NULL;
    if(t==NULL) t=s;
    else{
        p=t;
        while(p!=NULL){
            q=p;
            if(m<p->data)   p=p->left;
            else            p=p->right;
        }
        if(m<q->data)   q->left=s;
        else            q=q->right=s;
        }
    }


    return t;
}
int equeal(node t1,node t2){
    if(t1==NULL&&t2==NULL)  return 1;
    if(t1!=NULL&&t2==NULL)  return 0;
    if(t1==NULL&&t2!=NULL)  return 0;
    if(t1!=NULL&&t2!=NULL){
        if(t1->data!=t2->data)  return 0;
        if(equeal(t1->left,t2->left)==0)  return 0;
        if(equeal(t1->right,t2->right)==0)    return 0;
    }
    return 1;
}
int main()
{
    int n,m,i,flag;
    node t1,t2;
    while(cin>>n&&n){
    cin>>m;
    t1=NULL;
    t1=creat(t1,n);
    for(i=0;i<m;i++){
        t2=NULL; t2=creat(t2,n);
        flag=equeal(t1,t2);
        if(flag==1)
            cout<<"Yes"<<endl;
        else
            cout<<"No"<<endl;
        }
    }
    return 0;
}

还原二叉树

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/***
9
1 2 4 7 3 5 8 9 6
4 7 2 1 8 5 9 3 6
***/
#include <iostream>
#include <algorithm>
#include <stdio.h>
#include <string.h>
#define N 55
using namespace std;
struct BtreeNode{
    char data;
    struct BtreeNode* left;
    struct BtreeNode* right;
};
typedef struct BtreeNode* node;
typedef struct BtreeNode btree;
char qian[N],in[N];
int n;
node creat(char qian[],char in[],int n){
    int i;
    char root;
    if(n==0)    return NULL;
    root=qian[0];              ///root=qian[1];
    node t;
    t=new btree;
    t->data=root;
    for(i=0;i<n;i++)        ///for(i=1;i<=n;i++)
        if(in[i]==root)
            break;
    t->left=creat(qian+1,in,i);      ///t->left=creat(qian,in,i-1)
    t->right=creat(qian+i+1,in+i+1,n-i-1);     ///t->right=creat(qian+i,in+i,n-i);
    return t;
}
/*
void houxu(node tt){
    if(tt){
        houxu(tt->left);
        houxu(tt->right);
        printf("%c ",tt->data);
    }
}
int Depth(node &tt){
    int dep=0,depl=0,depr=0;
    if(!tt) dep=0;
    else{
    depl=Depth(tt->left);
    depr=Depth(tt->right);
    dep=1+(depl>depr?depl:depr);
    }
    return dep;
}
*/
int Depth(node &tt){
    int dep=0,del=0,der=0;
    if(!tt)
        dep=0;
    else{
        del=Depth(tt->left);
        der=Depth(tt->right);
        dep=1+(del>der?del:der);
    }
    return dep;
}
int main()
{
    int dep;
    scanf("%d%*c",&n);
    node tt=NULL;
    ///从0开始                     从1开始
    scanf("%s",qian);
    scanf("%s",in);
    tt=creat(qian,in,n);        ///tt=creat(qian,in,n);
    ///houxu(tt);
    ///printf("\n");
    dep=Depth(tt);
    cout<<dep<<endl;
    return 0;
}

树种统计

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用了map，不了解先学map

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <iomanip>
#include <map>
using namespace std;
int main()
{
    int n,i;
    char s[150];
    map<string,int>M;
    cin>>n;
    getchar();
    M.clear();
    for(i=0;i<n;i++){
        gets(s);
        M[s]++;
    }
    map<string,int>::iterator it;
    for(it=M.begin();it!=M.end();it++)
        cout<<it->first<<" "<<fixed<<setprecision(4)<<it->second*100.0/n<<"%"<<endl;
    return 0;
}

笛卡尔树

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#include <iostream>
#include <queue>
#include <string.h>
#define N 1005
#define INF 0x3f3f3f3f
using namespace std;
int a[N][4];
int p1[N],p2[N],j=1,l=1;
struct tree{
int x1,x2;
struct tree *h;
struct tree *left;
struct tree *right;
}u,v;
queue<tree>q;
struct tree* newtree(int n){
if(n==-1)
return NULL;
tree *t=new tree;
t->x1=a[n][0];  t->x2=a[n][1];  t->right=NULL;  t->left=NULL;
t->left=newtree(a[n][2]);
t->right=newtree(a[n][3]);
return t;
}
void min1(struct tree *t){
if(t==NULL) return ;
min1(t->left);
p1[j]=t->x1;
++j;
min1(t->right);
}
int main(){
int n;
cin>>n;
int k=0;
memset(p2,INF,sizeof(p2));
for(int i=0;i<n;i++){
            k+=i;
        cin>>a[i][0]>>a[i][1]>>a[i][2]>>a[i][3];
            if(a[i][2]>=0)
                k=k-a[i][2];
            if(a[i][3]>=0)
                k=k-a[i][3];

    }
    struct tree *t,*p;
    t=newtree(k);
    min1(t);    u.h=t;  u.x1=1; q.push(u);  p=t;
    while(!q.empty()){
    u=q.front();    q.pop();
    p=u.h;
    p2[u.x1]=p->x2;
    if(p->left!=NULL) {
    v.h=p->left;
    v.x1=u.x1*2;
    q.push(v);
    }
if(p->right!=NULL) {
    v.h=p->right;
    v.x1=u.x1*2+1;
    q.push(v);
    }
    }
    for(int i=1;i<=n;i++){
    if(i<=n-1&&p1[i]>p1[i+1]){
    cout<<"NO"<<endl;
    return 0;
    }
    if(p2[i]>p2[2*i]||p2[i]>p2[2*i+1]){
    cout<<"NO"<<endl;
    return 0;
    }
    }
    cout<<"YES"<<endl;
}

顺序存储的二叉树的最近的公共祖先问题

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#include <iostream>
#define N 1010
using namespace std;

int main()
{
    int n,i,j,k,x;
    int a[N];
    cin>>n;
    for(k=1;k<=n;k++)
        cin>>a[k];

    cin>>i>>j;
    while(i!=j){
        if(a[i]==0){
            x=i;
            break;
        }
        if(a[j]==0){
            x=j;
            break;
        }
        if(i>j)
            i=i/2;
        else
            j=j/2;

    }
    if(a[i]==0||a[j]==0)
        cout<<"ERROR: T["<<x<<"] is NULL"<<endl;
    else
        cout << i <<" "<< a[j] << endl;
    return 0;
}

List Leaves

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#include <iostream>
#include <queue>
#include <stdio.h>
#include <string.h>
using namespace std;
int a[20],l[20],r[20];
struct BtreeNode{
    int parent;
    struct BtreeNode* left;struct BtreeNode* right;
}u,v;
typedef struct BtreeNode* node;
typedef struct BtreeNode btree;
node creat(int i){
    node s;
    if(i==-1)
        return NULL;
    s=new btree;
    s->parent=i;
    s->left=creat(l[i]);
    s->right=creat(r[i]);
    return s;
}
int uuu=0;
void bfs(node t){
    queue<struct BtreeNode>q;
    node p,w;
    u.parent=t->parent;
    u.left=t->left;
    u.right=t->right;
    q.push(u);
    while(!q.empty()){
        u=q.front();q.pop();
        p=u.left;
        w=u.right;
        if(p==NULL&&w==NULL){
            uuu++;
            if(uuu==1)
                cout<<u.parent;
            else
                cout<<" "<<u.parent;
        }
        if(p!=NULL){
            v.parent=p->parent;
            v.left=p->left;
            v.right=p->right;
            q.push(v);
        }

        if(w!=NULL){
            v.parent=w->parent;
            v.left=w->left;
            v.right=w->right;
            q.push(v);
        }
    }

}
int main()
{
    int n,i;
    char c1,c2;
    cin>>n;
    getchar();
    for(i=0;i<n;i++){
        scanf("%c %c%*c",&c1,&c2);
        if(c1=='-') l[i]=-1;
        else{
                l[i]=c1-'0';
                a[l[i]]=1;
            }
        if(c2=='-') r[i]=-1;
        else{
                r[i]=c2-'0';
                a[r[i]]=1;
            }
    }
    for(i=0;i<n;i++)
        if(a[i]!=1)
        break;

    node t=NULL;
    t=creat(i);
    bfs(t);
    return 0;
}