C语言强化——链表（2）

目录

链表的应用：

• 栈
• 循环队列
• C语言实现动态数组
• 数组实现定长元素个数层次建树
• 队列实现不定元素个数层次建树 (*)

栈

栈（链表应用）

"stack.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct tag{
	int m_ival;
	struct tag *next;
}Node,*pNode;

typedef struct{
	pNode phead;//栈顶指针
	int size;
}Stack,*pStack;

void initStack(pStack);
void pop(pStack);
void push(pStack,int);
int top(pStack);
int empty(pStack);
int size(pStack);

"stack.c"

#include "stack.h"

void initStack(pStack p)
{
	memset(p,0,sizeof(Stack));
}
void pop(pStack p)
{
	if(!p->size)
	{
		printf("stack is empty\n");
		return;
	}
	p->phead=p->phead->next;
	p->size--;
}
void push(pStack p,int val)
{
	pNode pNew=(pNode)calloc(1,sizeof(Node));
	pNew->m_ival=val;
	if(NULL==p->phead)
	{
		p->phead=pNew;
	}else{
		pNew->next=p->phead;//新结点的next指向原有头结点
		p->phead=pNew;
	}
	p->size++;
}
int top(pStack p)
{
	return p->phead->m_ival;
}
int empty(pStack p)
{
	return !p->size;
}
int size(pStack p)
{
	return p->size;
}

"main.c"

#include "stack.h"

int main() {
	Stack s;
	initStack(&s);
	push(&s, 5);
	push(&s, 10);
	printf("Stack size is %d\n", size(&s));
	printf("Stack top val is %d\n", top(&s));
	pop(&s);
	printf("Stack top val is %d\n", top(&s));
	pop(&s);
	pop(&s);
	return 0;
}

循环队列

queue.h

#include <stdio.h>
#include <stdlib.h>

#define MaxSize 5
typedef int ElemType;
typedef struct{
	ElemType data[MaxSize];
	int front,rear;
}SqQueue;

void InitQueue(SqQueue*);
int EnQueue(SqQueue*,ElemType);
int DeQueue(SqQueue*,ElemType*);

queue.c

#include "queue.h"

void InitQueue(SqQueue* pq)
{
	pq->front=pq->rear=0;
}

int EnQueue(SqQueue* pq,ElemType val)
{
	if((pq->rear+1)%MaxSize==pq->front)
	{
		printf("queue is full\n");
		return 0;
	}
	pq->data[pq->rear]=val;
	pq->rear=(pq->rear+1)%MaxSize;
	return 1;
}
int DeQueue(SqQueue* pq,ElemType* x)
{
	if(pq->rear==pq->front)
	{
		printf("queue is empty\n");
		return 0;
	}
	*x=pq->data[pq->front];
	pq->front=(pq->front+1)%MaxSize;
	return 1;
}

main.c

#include "queue.h"

int main()
{
	SqQueue q;
	ElemType val;
	InitQueue(&q);
	EnQueue(&q,10);
	EnQueue(&q,7);
	EnQueue(&q,5);
	EnQueue(&q,3);
	EnQueue(&q,9);
	DeQueue(&q,&val);
	system("pause");
}

C语言实现动态数组

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct{
	char *p;
	int size;//当前放了多少数据
	int capacity;//容量大小，申请了多少空间
}DynArr;

#define N 10
int main()
{
	DynArr d;
	int i=0;
	d.size=0;
	d.capacity=N;
	d.p=(char*)malloc(d.capacity);
	while(scanf("%c",d.p+d.size)!=EOF)
	{
		d.size++;
		if(d.size==d.capacity)
		{
			d.capacity=d.capacity*2;
			d.p=(char*)realloc(d.p,d.capacity);
		}
	}
	d.p[d.size-1]='\0';
	printf("%s\n",d.p);
	system("pause");
}

队列实现不定元素个数层次建树 (*)

#include <stdio.h>
#include <stdlib.h>

typedef char ElemType;
typedef struct node{
	ElemType c;
	struct node *pleft;
	struct node *prgiht;
}Node,*pNode;

typedef struct que{
	pNode p;
	struct que *pNext;
}Que_t,*pQue_t;

//前序遍历
void preOrder(pNode p)
{
	if(p)
	{
		putchar(p->c);
		preOrder(p->pleft);
		preOrder(p->prgiht);
	}
}
int main()
{
	ElemType c;
	pQue_t queHead=NULL,queTail=NULL,queNew,queFree;
	pNode treeRoot=NULL,treeNew;
	while(scanf("%c",&c)!=EOF)
	{
		if(c=='\n')
		{
			break;
		}
		treeNew=(pNode)calloc(1,sizeof(Node));//给树的新结点申请空间
		treeNew->c=c;
		queNew=(pQue_t)calloc(1,sizeof(Que_t));//给队列的新结点申请空间
		queNew->p=treeNew;
		if(!treeRoot)
		{
			treeRoot=treeNew;//第一个结点作为树根
			queHead=queTail=queNew;//第一个结点作为队列头
		}else{

			if(NULL==queHead->p->pleft)
			{
				queHead->p->pleft=treeNew;
			}else if(NULL==queHead->p->prgiht)
			{
				queHead->p->prgiht=treeNew;
				//头部删除法
				queFree=queHead;
				queHead=queHead->pNext;
				free(queFree);
			}
			//尾插法
			queTail->pNext=queNew;
			queTail=queNew;
		}
	}
	preOrder(treeRoot);
	printf("\n");
	system("pause");
}

数组实现定长元素个数层次建树

#include<stdio.h>
#define N 10

typedef char ElemType;
typedef struct node {
	ElemType c;
	struct node *pleft;
	struct node *pright;
}Node, *pNode;

void preOrder(pNode p)
{
	if (p)
	{
		putchar(p->c);
		preOrder(p->pleft);
		preOrder(p->pright);
	}
}

int main() {
	ElemType c[N + 1] = "ABCDEFGHIJ";
	int i, j;
	pNode p[N];   //结构体指针数组
	pNode root;
	for (i = 0;i < N;++i) {
		p[i] = (pNode)calloc(1, sizeof(Node));
		p[i]->c = c[i];
	}
	root = p[0];
	j = 0;
	for (i = 1;i < N;++i) {
		if (NULL == p[j]->pleft) {
			p[j]->pleft = p[i];
		}
		else if (NULL == p[j]->pright) {
			p[j]->pright = p[i];
			j++;
		}
	}
	preOrder(root);
	return 0;
}