1、二叉树递归创建 ，二叉树先中后序遍历，二叉树计算节点，二叉树计算深度
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef char datatype;
typedef struct Node
{
datatype data;
struct Node *lchild;
struct Node *rchild;
}*Btree;
Btree create_node()
{
Btree s=(Btree)malloc(sizeof(struct Node));
if(s==NULL)
return NULL;
s->data='\0';
s->lchild=s->rchild=NULL;
return s;
}
Btree create_tree()
{
datatype element;
printf("please enter element:");
scanf(" %c",&element);
if(element=='#')
return NULL;
Btree tree=create_node();
tree->data=element;
//循环创建左孩子
tree->lchild=create_tree();
//循环创建右孩子
tree->rchild=create_tree();
return tree;
}
//先序遍历
void first(Btree tree)
{
if(tree==NULL)
return;
printf("%c",tree->data);
first(tree->lchild);
first(tree->rchild);
}
//中序
void mid(Btree tree)
{
if(tree==NULL)
return;
mid(tree->lchild);
printf("%c",tree->data);
mid(tree->rchild);
}
//后序
void last(Btree tree)
{
if(tree==NULL)
return;
last(tree->lchild);
last(tree->rchild);
printf("%c",tree->data);
}
//计算总节点
void count(Btree tree,int *n0,int *n1,int *n2)
{
if(tree==NULL)
return;
if(!tree->lchild && !tree->rchild)
++*n0;
else if(tree->lchild && tree->rchild)
++*n2;
else
++*n1;
count(tree->lchild,n0,n1,n2);
count(tree->rchild,n0,n1,n2);
}
//计算深度
int high(Btree tree)
{
if(tree==NULL)
return 0;
int left=1+high(tree->lchild);
int right=1+high(tree->rchild);
return left>right?left:right;
}
int main(int argc, const char *argv[])
{
Btree tree=create_tree();
//先序（根左右）
first(tree);
puts("");
//中序
mid(tree);
puts("");
//后序
last(tree);
puts("");
//计算总节点
int n0,n1,n2;
n0=n1=n2=0;
count(tree,&n0,&n1,&n2);
printf("n0=%d,n1=%d,n2=%d,n=%d\n",n0,n1,n2,n0+n1+n2);
//计算深度
int len=high(tree);
printf("len=%d\n",len);
return 0;
}
2、编程实现快速排序降序
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
//一次比较
int one_sort(int *arr,int low,int high)
{
int key=*(arr+low);
while(low<high)
{
while(low<high&&key>=*(arr+high))
{
high--;
}
*(arr+low)=*(arr+high);
while(low<high&&key<=*(arr+low))
{
low++;
}
*(arr+high)=*(arr+low);
}
*(arr+low)=key;
return low;
}
void quick_sort(int *arr,int low,int high)
{
if(low>=high)
return;
//一次比较
int mid=one_sort(arr,low,high);
//递归左边子序列
quick_sort(arr,low,mid-1);
//递归右边子序列
quick_sort(arr,mid+1,high);
}
int main(int argc, const char *argv[])
{
int arr[]={12,454,23,77,34,67,48};
int len=sizeof(arr)/sizeof(arr[0]);
quick_sort(arr,0,len-1);
for(int i=0;i<len;i++)
{
printf("%d ",arr[i]);
}
puts("");
return 0;
}
3、思维导图
