A.求二叉樹的層次遍歷
#include <stdio.h>
#include <stdlib.h>
#include<string.h>
struct tree
{
    char data;
    struct tree*left,*right;
}*link[54];
char str1[54],str2[54];
struct tree*getbuild(int len,char *str1,char *str2)
{
    if(len==0)return NULL;//後序遍歷和還原二叉樹，在還原的過程中就後序遍歷了
    struct tree*root;
    root=(struct
 
 tree*)malloc(sizeof(struct tree));
    root->data=str1[0];
    int i;
    for(i=0;i<len;i++)
    {
        if(str2[i]==root->data)
            break;//找結點，知道後就退出
    }
    root->left=getbuild(i,str1+1,str2);//左子樹的長度，左子樹在str1中的位置，左子樹在str2中的位置
    root->right=getbuild(len-i-1,str1+i+1,str2+i+1
 
);
    return root;
}
void ceng(struct tree*root)//層序遍歷，入隊，先讓自己的左右孩子入隊後自己再出隊
{
    if(root)
    {
        int i=0,j=0;
        link[j++]=root;
        while(i<j)//當沒有可以入隊的元素的時候，就出隊
        {
            if(link[i])
            {
                link[j++]=link[i]->left;
                link[j++]=link[i]->right;
                printf
 
("%c",link[i]->data);
            }
            i++;
        }
    }
}
int main()
{
    int t,len;
    scanf("%d",&t);
    while(t--)
    {
        struct tree*root;
        scanf("%s%s",str1,str2);
        len=strlen(str2);
        root=getbuild(len,str1,str2);
        ceng(root);
        printf("\n");
    }
    return 0;
}
B.資料結構實驗之求二叉樹後序遍歷和層次遍歷
#include <stdio.h>
#include <stdlib.h>
#include<string.h>
struct tree
{
    char data;
    struct tree*left,*right;
}*link[54];
char str1[54],str2[54];
struct tree*getbuild(int len,char *str1,char *str2)
{
    if(len==0)return NULL;//後序遍歷和還原二叉樹，在還原的過程中就後序遍歷了
    struct tree*root;
    root=(struct tree*)malloc(sizeof(struct tree));
    root->data=str1[0];
    int i;
    for(i=0;i<len;i++)
    {
        if(str2[i]==root->data)
            break;//找結點，知道後就退出
    }
    root->left=getbuild(i,str1+1,str2);//左子樹的長度，左子樹在str1中的位置，左子樹在str2中的位置
    root->right=getbuild(len-i-1,str1+i+1,str2+i+1);
    printf("%c",root->data);
    return root;
}
void ceng(struct tree*root)//層序遍歷，入隊，先讓自己的左右孩子入隊後自己再出隊
{
    if(root)
    {
        int i=0,j=0;
        link[j++]=root;
        while(i<j)//當沒有可以入隊的元素的時候，就出隊
        {
            if(link[i])
            {
                link[j++]=link[i]->left;
                link[j++]=link[i]->right;
                printf("%c",link[i]->data);
            }
            i++;
        }
    }
}
int main()
{
    int t,len;
    scanf("%d",&t);
    while(t--)
    {
        struct tree*root;
        scanf("%s%s",str1,str2);
        len=strlen(str2);
        root=getbuild(len,str1,str2);
        printf("\n");
        ceng(root);
        printf("\n");
    }
    return 0;
}
C.求二叉樹的先序遍歷
#include <stdio.h>
#include <stdlib.h>
struct tree
{
    char data;
    struct tree *left,*right;
}*root;
char str1[54],str2[54];
struct tree*getbuild(int len,char *str1,char *str2)
{
    if(len==0)
    {
        return NULL;
    }
    struct tree *root;
    root=(struct tree *)malloc(sizeof(struct tree));
    root->data=str2[len-1];
    int i;
    for(i=0; i<len; i++)
    {
        if(str1[i]==root->data)
        {
            break;
        }
    }
    printf("%c",root->data);
    root->left=getbuild(i,str1,str2);
    root->right=getbuild(len-1-i,str1+i+1,str2+i);
    return root;
};
int main()
{
    int t,len;
    while(~scanf("%d",&t))
    {
        while(t--)
        {
            scanf("%s %s",str1,str2);
            len=strlen(str2);
            root=(struct tree *)malloc(sizeof(struct tree));
            getbuild(len,str1,str2);
            printf("\n");

        }
    }
    return 0;
}
D.資料結構實驗之二叉樹四：（先序中序）還原二叉樹
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
struct tree
{
    char data;
    struct tree*left,*right;
}*root;
char str1[51],str2[52];
struct tree*getbuild(int len,char *str1,char *str2)
{
    if(len==0)return NULL;
    struct tree*root;
    root=(struct tree*)malloc(sizeof(struct tree));
    root->data=str1[0];
    int i;
    for(i=0;i<len;i++)
    {
        if(str2[i]==root->data)
            break;
    }
    root->left=getbuild(i,str1+1,str2);
    root->right=getbuild(len-i-1,str1+i+1,str2+i+1);
    return root;
}//利用先序和中序來實現後序二叉樹的還原
int depth(struct tree*root)
{
    int x,y;
    if(root==NULL)return 0;
    else
    {
        x=depth(root->left);
        y=depth(root->right);
        return (x>y)?(x+1):(y+1);
    }//執行到最底層，從最底層開始往上加
}
int main()
{
    int n,len,dep;
    while(~scanf("%d",&n))
    {
        scanf("%s%s",str1,str2);
        len=strlen(str2);
        root=getbuild(len,str1,str2);
        dep=depth(root);
        printf("%d\n",dep);
    }
    return 0;
}
E.資料結構實驗之二叉樹三：統計葉子數
#include<stdio.h>
#include<stdlib.h>
struct tree
{
    char data;
    struct tree*left,*right;
}*root;
char s[52];
int ans,count;
struct tree*front_create()
{
    struct tree*root;//必須要有
    char c=s[ans++];
    if(c==',')return NULL;
    else
    {
        root=(struct tree*)malloc(sizeof(struct tree));
        root->data=c;
        root->left=front_create();
        root->right=front_create();
    }
    return root;//每次都是創造一個新的root，然後對root進行賦值，一層層的把root賦給左孩子，右孩紙，，最後賦值給總的root，一棵樹就形成了
}
int searchleaf(struct tree*root)
{
    if(root)
    {
        if(root->left==NULL&&root->right==NULL)
            count++;
        searchleaf(root->left);
        searchleaf(root->right);
    }
    return count;
}
int main()
{
    while(~scanf("%s",s))
    {
        ans=0;
        count=0;
        root=front_create();
        printf("%d\n",searchleaf(root));
    }
    return 0;
}
F.資料結構上機測試4.1:二叉樹的遍歷與應用1
#include<stdio.h>
#include<stdlib.h>
struct tree
{
    char data;
    struct tree*left,*right;
}*root;
char s[52];
int ans,count;
struct tree*front_create()
{
    struct tree*root;//必須要有
    char c=s[ans++];
    if(c==',')return NULL;
    else
    {
        root=(struct tree*)malloc(sizeof(struct tree));
        root->data=c;
        root->left=front_create();
        root->right=front_create();
    }
    return root;//每次都是創造一個新的root，然後對root進行賦值，一層層的把root賦給左孩子，右孩紙，，最後賦值給總的root，一棵樹就形成了
}
int searchleaf(struct tree*root)
{
    if(root)
    {
        if(root->left==NULL&&root->right==NULL)
            count++;
        searchleaf(root->left);
        searchleaf(root->right);
    }
    return count;
}
int main()
{
    while(~scanf("%s",s))
    {
        ans=0;
        count=0;
        root=front_create();
        printf("%d\n",searchleaf(root));
    }
    return 0;
}

G.資料結構實驗之二叉樹五：層序遍歷
#include<stdio.h>
#include<stdlib.h>
struct tree
{
    char data;
    struct tree*left,*right;
}*root,*link[54];
char s[54];
int ans;
struct tree*front_create()
{
    struct tree*root;
    char c=s[ans++];
    if(c==',')root=NULL;
    else
    {
        root=(struct tree*)malloc(sizeof(struct tree));
        root->data=c;
        root->left=front_create();
        root->right=front_create();
    }
    return root;
}//先序建立一個樹
void ceng(struct tree*root)
{

    if(root)
    {
        int i=0,j=0;
        link[j++]=root;//先把頭放上
        while(i<j)
        {
            if(link[i])
            {
                link[j++]=link[i]->left;
                link[j++]=link[i]->right;
                printf("%c",link[i]->data);
            }
            i++;
        }
    }
}//利用佇列層序輸出
int main()
{
    int t;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%s",s);
        ans=0;
        root=front_create();
        ceng(root);
        printf("\n");
    }
    return 0;
}
H.資料結構實驗之二叉樹的建立與遍歷
#include<stdio.h>
#include<stdlib.h>
struct tree
{
    char data;
    struct tree*right,*left;
}*link[54];
char s[54];
int ans,flag;
struct tree*front_create()
{
    struct tree*root;
    char c=s[ans++];
    if(c==',')root=NULL;//遞迴的邊界，輸入的數的最後肯定是','
    else
    {
        root=(struct tree*)malloc(sizeof(struct tree));
        root->data=c;
        root->left=front_create();
        root->right=front_create();
    }
    return root;
}
int depth(struct tree*root)//求深度
{
    int x,y;
    if(!root)return 0;
    else
    {
        x=depth(root->left);
        y=depth(root->right);
        return x>y?x+1:y+1;
    }
}
void mid(struct tree*root)//中序遍歷
{
    if(root)
    {
        mid(root->left);
        printf("%c",root->data);
        mid(root->right);
    }
}
void after(struct tree*root)//後序遍歷
{
    if(root)
    {
        after(root->left);
        after(root->right);
        printf("%c",root->data);
    }
}
int searchleaf(struct tree*root)//尋找葉子結點，在層序遍歷的基礎上加點操作即可
{
    if(root)
    {
        int i=0,j=0;
        link[j++]=root;
        while(i<j)
        {
            if(link[i])
            {
                if(link[i]->left==NULL&&link[i]->right==NULL)
                    flag++;
                else
                {
                    link[j++]=link[i]->left;
                    link[j++]=link[i]->right;
                }
            }
            i++;
        }
    }
    return flag;
}
int main()
{
    scanf("%s",s);
    flag=0,ans=0;
    struct tree*root;
    root=front_create();
    mid(root);
    printf("\n");
    after(root);
    printf("\n");
    printf("%d\n",searchleaf(root));
    printf("%d\n",depth(root));
    return 0;
}
I.資料結構實驗之二叉樹一：樹的同構
#include<stdio.h>
#include<stdlib.h>
#define max 21
int n1,n2;
struct node
{
    char key;
    int left,right;
}tree1[max],tree2[max];
void buildtree(struct node tree[],int n)
{
    int i;
    char s[2];
    for(i=0;i<n;i++)
    {
        scanf("%s",s);
        tree[i].key=s[0];
        scanf("%s",s);
        if(s[0]=='-')
        {
            tree[i].left=11;
        }
        else tree[i].left=s[0]-'0';
        scanf("%s",s);
        if(s[0]=='-')
        {
            tree[i].right=11;
        }
        else tree[i].right=s[0]-'0';
    }
}
int checkc(int i,int j)
{
    if(tree1[tree1[i].left].key==tree2[tree2[j].left].key&&tree1[tree1[i].right].key==tree2[tree2[j].right].key)
        return  1;
    if(tree1[tree1[i].left].key==tree2[tree2[j].right].key&&tree1[tree1[i].right].key==tree2[tree2[j].left].key)
        return 1;
    return 0;
}
int check(struct node tree1[],int n1,struct node tree2[],int n2)
{
    int i,j;
    for(i=0;i<n1;i++)
    {
        for(j=0;j<n2;j++)
        {
            if(tree1[i].key==tree2[j].key)
            {
                if(checkc(i,j))break;//左右孩子相同或者交換之後的左右對應相同，就行了，看下一個結點
                else return 0;//一旦有一個點不相同，就不是同構
            }
        }
        if(j==n2)return 0;//如果找遍了都沒找到，那就是沒有了
    }
    return 1;//整棵樹都滿足就是同構了
}
int main()
{
    while(~scanf("%d",&n1))
    {
        buildtree(tree1,n1);
        scanf("%d",&n2);
        buildtree(tree2,n2);
        if(n1!=n2)printf("No\n");
        else if(check(tree1,n1,tree2,n2))
            printf("Yes\n");
        else printf("No\n");
    }
    return 0;
}
J.資料結構實驗之二叉樹八：（中序後序）求二叉樹的深度
#include <stdio.h>
#include <stdlib.h>

#include <string.h>
struct tree
{
    char data;
    struct tree *left,*right;
}*root;
char str1[54],str2[54];
struct tree*getbuild(int len,char *str1,char *str2)
{
    if(len==0)
    {
        return NULL;
    }
    struct tree *root;
    root=(struct tree *)malloc(sizeof(struct tree));
    root->data=str2[len-1];
    int i;
    for(i=0; i<len; i++)
    {
        if(str1[i]==root->data)
        {
            break;
        }
    }
    root->left=getbuild(i,str1,str2);
    root->right=getbuild(len-1-i,str1+i+1,str2+i);
    return root;
};
int depth(struct tree *root)
{
    int x,y;
    if(root==NULL)
    {
        return 0;
    }
    else
    {
        x=depth(root->left);
        y=depth(root->right);
        return (x>y)?(x+1):(y+1);
    }
}
int main()
{
    int t,len,m;
    while(~scanf("%d",&t))
    {
        while(t--)
        {
            struct tree *root;
            scanf("%s %s",str1,str2);
            len=strlen(str2);
            root=getbuild(len,str1,str2);
            m=depth(root);
            printf("%d\n",m);
        }
    }
    return 0;
}

K.資料結構實驗之二叉樹七：葉子問題
#include<stdio.h>
#include<stdlib.h>
struct tree
{
    char data;
    struct tree*left,*right;
}*link[54],*root;
char s[54];
int ans;
struct tree*front_create()
{
    struct tree*root;
    char c=s[ans++];
    if(c==',')root=NULL;
    else
    {
        root=(struct tree*)malloc(sizeof(struct tree));
        root->data=c;
        root->left=front_create();
        root->right=front_create();
    }
    return root;
}
void ceng(struct tree*root)
{
    if(root)
    {
        int i=0,j=0;
        link[j++]=root;
        while(i<j)
        {
            if(link[i])
            {
                if(link[i]->left==NULL&&link[i]->right==NULL)
                   printf("%c",link[i]->data);
                else
                {
                    link[j++]=link[i]->left;
                    link[j++]=link[i]->right;
                }
            }
            i++;
        }
    }
}
int main()
{
    while(~scanf("%s",s))
    {
        ans=0;
        struct tree*root;
        root=front_create();
        ceng(root);
        printf("\n");
    }
    return 0;
}
L.資料結構實驗之二叉樹二：遍歷二叉樹
#include<stdio.h>
#include<stdlib.h>
struct tree
{
    char data;
    struct tree*right,*left;
}*link[54];
char s[54];
int ans,flag;
struct tree*front_create()
{
    struct tree*root;
    char c=s[ans++];
    if(c==',')root=NULL;//遞迴的邊界，輸入的數的最後肯定是','
    else
    {
        root=(struct tree*)malloc(sizeof(struct tree));
        root->data=c;
        root->left=front_create();
        root->right=front_create();
    }
    return root;
}
void mid(struct tree*root)//中序遍歷
{
    if(root)
    {
        mid(root->left);
        printf("%c",root->data);
        mid(root->right);
    }
}
void after(struct tree*root)//後序遍歷
{
    if(root)
    {
        after(root->left);
        after(root->right);
        printf("%c",root->data);
    }
}
int main()
{
    while(~scanf("%s",s))
    {
        ans=0;
        struct tree*root;
        root=front_create();
        mid(root);
        printf("\n");
        after(root);
        printf("\n");
    }

    return 0;
}