[单链表]统计文本中英文单词出现次数，并输出前200个单词及其出现次数

统计文本中各英文单词出现次数，并按词频逆序排列。

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>

#define SIZE 50

typedef struct words
{
	char str[SIZE];	//单词最长100个
	int count;
	struct words *next;
}Words;


// 初始化链表
Words* InitWord()
{
	Words *headWord = (Words*)malloc(sizeof(Words));
	strcpy(headWord->str,"");
	headWord->count = 0;
	headWord->next = NULL;
	return headWord;
}

// 增加新单词
void AddWord(Words *headWord,const char *str)//头插入
{
	Words *pos = headWord->next;	//储存当前第一个结构体的指针
	Words *newWord = (Words*)malloc(sizeof(Words));
	strcpy(newWord->str,str);
	headWord->next = newWord;
	if(pos == NULL)	newWord->next = NULL;//第一个单词，储存在链表尾部，next指向空
	else			newWord->next = pos;
	newWord->count=1;
}

int CheckStr(Words *headWord,const char *str)//检查单词是否出现过，若出现单词数量加一，返回1，没出现返回0
{
	Words *p = headWord->next;
	if(headWord->next == NULL)	
		{
			AddWord(headWord,str);
			return 1;
		}
	while(strcmp(p->str,str) != 0)
	{
		p = p->next;
		if(p == NULL)	break;
	}
	if(p == NULL)	return 0;//没有该单词，返回0标记
	else
	{
		++(p->count);	//已有单词，数量加一
		return 1;
	}
	return -1;			//异常出错
}

// 读单词，该函数每次读取一个单词
int ReadWord(FILE *fp,int *plen,char *str)
{
	fseek(fp, *plen, SEEK_SET);
	unsigned char ch;
	//if( feof(fp) )	//文件结束
 //   { 
 //       return 0;
 //   }
	int flg_eof = 0;
	int i=0;		// i 表示index
	while(fread(&ch,sizeof(char),1,fp) != 0)	//注：isalpha(unsigned(ch))，需要强制转换
	{
		if(!isalpha(unsigned(ch)) && i == 0)	continue;//排除单词 不是字母 无法读取问题
		if(isalpha(unsigned(ch)) || ch == '\'')//类似I'm中的 ' 符号，有且只能有一个
		{
			flg_eof = 1;	// 标记是否读过单词
			str[i++] = ch;
		}
		else
		{
			break;
		}
	}
	if(flg_eof == 0)	return 0;	//没有读文件，文件结尾了
	str[i] = '\0';
	*plen = ftell(fp);	// 对于文件首的偏移字节数
	return *plen;
}

// 读取文件，调用“读取单词函数”，每读取一个单词检查是否需要 添加新单词 或 计数+1
void ReadFile(Words *headWord,char *name)//文件操作，从文件中读取单词
{
	FILE *fp ;
	int len = 0;		//标记文件指针在文件中的位置
	if((fp= fopen(name,"r")) == NULL)
	{
		fp = fopen(name, "w+");/* 如果创建失败，新建一个文件  w+:可读写
					文件存在则文件长度清为零，文件不存在时创建一个   */
	}

	char str[SIZE];
	while(ReadWord(fp,&len,str) != 0)//fscanf(fp,"%s",str) != EOF
	{
		if(CheckStr(headWord,str) == 0)	//没有该单词，新增一个
		{
			AddWord(headWord,str);
		}	

	}

	fclose(fp);
}

//单词交换顺序
void SwapWord(Words *posWord,Words *posNext)
{
	// 交换单词
	char tmpWord[SIZE]="";
	strcpy(tmpWord ,posWord->str);  
	strcpy(posWord->str, posNext->str);
	strcpy(posNext->str, tmpWord);

	// 交换对应单词计数
	int tmpCount;
	tmpCount	   = posWord->count;
	posWord->count = posNext->count;
	posNext->count = tmpCount;

}
// 单词排序，按计数从大到小
void WordsSort(Words *headWord)
{
	if(headWord->next == NULL)	return;
	Words *flg_word = NULL;
	int flag;
	while(flg_word != headWord->next)
	{
		flag = 0;
		Words *pos = headWord->next;
		Words *pos_next = pos->next;

		while(pos_next != NULL)
		{
			if(pos->count < pos_next->count)
			{
				SwapWord(pos,pos_next);
				flag = 1;
			}

			if(pos_next->next == flg_word)	//仿冒泡的i<n-i-1. 相当于flg_word每次减一
			{
				flg_word = pos_next;
				break;	//可有可无，while中已有条件
			}
			pos = pos->next;
			pos_next = pos_next->next;

		}
		if(flag == 0)	break;
	}

}

// 打印词频排行榜
void PrintWords(Words *headWord,const char *name)
{
	Words *pMove = headWord->next;
	if(headWord->next == NULL)	return;
	int count = 0;
	printf("\t<<%s>>中出现的最高频率的单词:\n",name);
	printf("\t单词：\t\t\t\t\t\t出现次数：\n");
	while(pMove != NULL && count<200)
	{
		printf("\t%-50s%d\n",pMove->str,pMove->count);
		pMove = pMove->next;
		count++;
	}
	printf("\n");
}

//释放链表
void free_Word(Words* headNode)
{
	Words *point = NULL;
	while(headNode != NULL)
	{
		point = headNode;//指向所释放的空间
		headNode = headNode->next;//指针后移
		free(point);
	}
}



int main()
{
	Words *headWord = InitWord();		//初始化链表,创建表头
	char bookName[][100] = {"小王子.txt","CountWords.cpp","test.txt","Harry Potter and The Half-Blood Prince.txt" };
										//当前文件*.cpp文件    //哈利波特
	ReadFile(headWord,bookName[0]);		//文件操作
	WordsSort(headWord);				//排序
	PrintWords(headWord,bookName[0]);	//打印
	free_Word(headWord);				//释放链表
	return 0;
}

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文件下载：
小王子.txt
链接：https://wwa.lanzous.com/icWhOe8z34j
Harry Potter and The Half-Blood Prince.txt
链接：https://wwa.lanzous.com/inix8e8z33i