- C - 在单词数组中,如果单词存在,就排除单词

117 4

数组形式中最常见的单词(Top 100):


#define NUMBER_OF_STRING 100


#define MAX_STRING_SIZE 50



char commonWords[NUMBER_OF_STRING][MAX_STRING_SIZE] = {"the","be","to","of","and","a","in","that","have","I","it","for","not","on","with","he","as","you","do","at","this","but","his","by","from","they","we","say","her","she","or","an","will","my","one","all","would","there","their","what","so","up","out","if","about","who","get","which","go","me","when","make","can","like","time","no","just","him","know","take","people","into","year","your","good","some","could","them","see","other","than","then","now","look","only","come","its","over","think","also","back","after","use","two","how","our","work","first","well","way","even","new","want","because","any","these","give","day","most","us"};



代码示例:


/**


 * C program to count occurrences of all words in a file.


 */


#include <stdio.h>


#include <stdlib.h>


#include <string.h>


#include <ctype.h>


#include <limits.h>



#define MAX_WORD 20000 /* max word size */


#define MAX_WORDS 8 /* initial number of struct to allocate */



#ifndef PATH_MAX


#define PATH_MAX 2048 /* max path (defined for Linux in limits.h) */


#endif



typedef struct { /* use a struct to hold */


 char word[MAX_WORD]; /* lowercase word, and */


 int cap, count; /* if it appeast capitalized, and its count */


} words_t;



char *strlwr (char *str) /* no need for unsigned char */


{


 char *p = str;



 while (*p) {


 *p = tolower(*p);


 p++;


 }



 return str;


}



int main (void) {



 FILE *fptr;


 char path[PATH_MAX], word[MAX_WORD];


 size_t i, len, index = 0, max_words = MAX_WORDS;



 /* pointer to allocated block of max_words struct initialized zero */


 words_t *words = calloc (max_words, sizeof *words);


 if (!words) { /* valdiate every allocation */


 perror ("calloc-words");


 exit (EXIT_FAILURE);


 }



 /* Input file path */


 printf ("Enter file path:");


 if (scanf ("%s", path) != 1) { /* validate every input */


 fputs ("error: invalid file path or cancellation.n", stderr);


 return 1;


 }



 fptr = fopen (path,"r"); /* open file */


 if (fptr == NULL) { /* validate file open */


 fputs ("Unable to open file.n"


"Please check you have read privileges.n", stderr);


 exit (EXIT_FAILURE);


 }



 while (fscanf (fptr,"%s", word) == 1) { /* while valid word read */


 int iscap = 0, isunique = 1; /* is captial, is unique flags */



 if (isupper (*word)) /* is the word uppercase */


 iscap = 1;



 /* remove all trailing punctuation characters */


 len = strlen (word); /* get length */


 while (len && ispunct(word[len - 1])) /* only if len > 0 */


 word[--len] = 0;



 strlwr (word); /* convert word to lowercase */



 /* check if word exits in list of all distinct words */


 for (i = 0; i < index; i++) {


 if (strcmp(words[i].word, word) == 0) {


 isunique = 0; /* set unique flag zero */


 if (iscap) /* if capital flag set */


 words[i].cap = iscap; /* set capital flag in struct */


 words[i].count++; /* increment word count */


 break; /* bail - done */


 }


 }


 if (isunique) { /* if unique, add to array, increment index */


 if (index == max_words) { /* is realloc needed? */


 /* always use a temporary pointer with realloc */


 void *tmp = realloc (words, 2 * max_words * sizeof *words);


 if (!tmp) { /* validate every allocation */


 perror ("realloc-words");


 break; /* don't exit, original data still valid */


 }


 words = tmp; /* assign reallocated block to words */


 /* (optional) set all new memory to zero */


 memset (words + max_words, 0, max_words * sizeof *words);


 max_words *= 2; /* update max_words to reflect new limit */


 }


 memcpy (words[index].word, word, len + 1); /* have len */


 if (iscap) /* if cap flag set */


 words[index].cap = iscap; /* set capital flag in struct */


 words[index++].count++; /* increment count & index */


 }


 }


 fclose (fptr); /* close file */



 /*


 * Print occurrences of all words in file.


 */


 puts ("nOccurrences of all distinct words with Cap in file:");


 for (i = 0; i < index; i++) {


 if (words[i].cap) {


 strcpy (word, words[i].word);


 *word = toupper (*word);


 /*


 * %-15s prints string in 15 character width.


 * - is used to print string left align inside


 * 15 character width space.


 */


 printf("%-8d %sn", words[i].count, word);


 }


 }


 free (words);



 return 0;


}



要测试的文本文件: (car 。txt )


A car (or automobile) is a wheeled motor vehicle used for transportation. Most definitions of car say they run primarily on roads, seat one to eight people, have four tires, and mainly transport people rather than goods.[2][3]



Cars came into global use during the 20th century, and developed economies depend on them. The year 1886 is regarded as the birth year of the modern car when German inventor Karl Benz patented his Benz Patent-Motorwagen. Cars became widely available in the early 20th century. One of the first cars accessible to the masses was the 1908 Model T, an American car manufactured by the Ford Motor Company. Cars were rapidly adopted in the US, where they replaced animal-drawn carriages and carts, but took much longer to be accepted in Western Europe and other parts of the world.



Cars have controls for driving, parking, passenger comfort, and a variety of lights. Over the decades, additional features and controls have been added to vehicles, making them progressively more complex. These include rear reversing cameras, air conditioning, navigation systems, and in-car entertainment. Most cars in use in the 2010s are propelled by an internal combustion engine, fueled by the combustion of fossil fuels. Electric cars, which were invented early in the history of the car, began to become commercially available in 2008.



There are costs and benefits to car use. The costs include acquiring the vehicle, interest payments (if the car is financed), repairs and maintenance, fuel, depreciation, driving time, parking fees, taxes, and insurance.[4] The costs to society include maintaining roads, land use, road congestion, air pollution, public health, health care, and disposing of the vehicle at the end of its life. Road traffic accidents are the largest cause of injury-related deaths worldwide.[5]



The benefits include on-demand transportation, mobility, independence, and convenience.[6] The societal benefits include economic benefits, such as job and wealth creation from the automotive industry, transportation provision, societal well-being from leisure and travel opportunities, and revenue generation from the taxes. People's ability to move flexibly from place to place has far-reaching implications for the nature of societies.[7] There are around 1 billion cars in use worldwide. The numbers are increasing rapidly, especially in China, India and other newly industrialized countries.[8]



输出:


Occurrences of all distinct words with Cap in file:


3 A


2 Motor


2 Most


2 One


8 Cars


29 The


1 German


1 Karl


2 Benz


1 Patent-motorwagen


1 Model


1 T


1 American


1 Ford


1 Company


1 Us


1 Western


1 Europe


1 Over


1 These


1 Electric


2 There


2 Road


1 People's


1 China


1 India



预期输出:(仅例子)


2 Motor


1 German


1 Karl


2 Benz


1 Patent-motorwagen


1 Model


1 T


1 American


1 Ford


1 Company



编辑更新:可能的解决方案:


// skip the word if it is a common word


for (int i = 0; i < NUMBER_OF_STRING; i++) {


 if (strcmp(word, commonWords[i])==0) {


 continue;


 }


}



时间: 原作者:

117 5

一种稍微更有效的方法是使用对strstr的单个调用,而不是尝试与前100个最常见的单词每一个进行比较。因为你知道这100个最常见的单词,而且它们不会改变,你可以很容易地确定最长的单词是7个字符,换句话说,你只需测试word是否是最常见的,如果它小于:


#define TOP_LEN 8 /* longest string in TOP100 + nul-character */



由于单词不改变,你可以继续:


const char TOP100[] =" the be to of and a in that have i it for not on with"


" he as you do at this but his by from they we say her she or"


" an will my one all would there their what so up out if about"


" who get which go me when make can like time no just him know"


" take people into year your good some could them see other"


" than then now look only come its over think also back after"


" use two how our work first well way even new want because"


" any these give day most us";



(注意:你也可以使用常量文本 #define TOP100" the ... us"

使用100最常用单词的常量字符串,唯一需要的是,


 ...


 strlwr (word); /* convert word to lowercase */



 /* check against 100 most common words (TOP100) */


 if (len < TOP_LEN) { /* word less than TOP_LEN? */


 char teststr[TOP_LEN * 2]; /* buffer for" word" */


 sprintf (teststr," %s", word); /* create teststr */


 if (strstr (TOP100, teststr)) /* check if in TOP100 */


 continue; /* if so, get next word */


 }


 ...



将它完全放在你的代码中:


/**


 * C program to count occurrences of all words in a file.


 */


#include <stdio.h>


#include <stdlib.h>


#include <string.h>


#include <ctype.h>


#include <limits.h>



#define MAX_WORD 20000 /* max word size */


#define MAX_WORDS 8 /* initial number of struct to allocate */


#define TOP_LEN 8 /* longest string in TOP100 */



#ifndef PATH_MAX


#define PATH_MAX 2048 /* max path (defined for Linux in limits.h) */


#endif



const char TOP100[] =" the be to of and a in that have i it for not on with"


" he as you do at this but his by from they we say her she or"


" an will my one all would there their what so up out if about"


" who get which go me when make can like time no just him know"


" take people into year your good some could them see other"


" than then now look only come its over think also back after"


" use two how our work first well way even new want because"


" any these give day most us";



typedef struct { /* use a struct to hold */


 char word[MAX_WORD]; /* lowercase word, and */


 int cap, count; /* if it appeast capitalized, and its count */


} words_t;



char *strlwr (char *str) /* no need for unsigned char */


{


 char *p = str;



 while (*p) {


 *p = tolower(*p);


 p++;


 }



 return str;


}



int main (void) {



 FILE *fptr;


 char path[PATH_MAX], word[MAX_WORD];


 size_t i, len, index = 0, max_words = MAX_WORDS;



 /* pointer to allocated block of max_words struct initialized zero */


 words_t *words = calloc (max_words, sizeof *words);


 if (!words) { /* valdiate every allocation */


 perror ("calloc-words");


 exit (EXIT_FAILURE);


 }



 /* Input file path */


 printf ("Enter file path:");


 if (scanf ("%s", path) != 1) { /* validate every input */


 fputs ("error: invalid file path or cancellation.n", stderr);


 return 1;


 }



 fptr = fopen (path,"r"); /* open file */


 if (fptr == NULL) { /* validate file open */


 fputs ("Unable to open file.n"


"Please check you have read privileges.n", stderr);


 exit (EXIT_FAILURE);


 }



 while (fscanf (fptr,"%s", word) == 1) { /* while valid word read */


 int iscap = 0, isunique = 1; /* is captial, is unique flags */



 if (isupper (*word)) /* is the word uppercase */


 iscap = 1;



 /* remove all trailing punctuation characters */


 len = strlen (word); /* get length */


 while (len && ispunct(word[len - 1])) /* only if len > 0 */


 word[--len] = 0;



 strlwr (word); /* convert word to lowercase */



 /* check against 100 most common words (TOP100) */


 if (len < TOP_LEN) { /* word less than TOP_LEN? */


 char teststr[TOP_LEN * 2]; /* buffer for" word" */


 sprintf (teststr," %s", word); /* create teststr */


 if (strstr (TOP100, teststr)) /* check if in TOP100 */


 continue; /* if so, get next word */


 }



 /* check if word exits in list of all distinct words */


 for (i = 0; i < index; i++) {


 if (strcmp(words[i].word, word) == 0) {


 isunique = 0; /* set unique flag zero */


 if (iscap) /* if capital flag set */


 words[i].cap = iscap; /* set capital flag in struct */


 words[i].count++; /* increment word count */


 break; /* bail - done */


 }


 }


 if (isunique) { /* if unique, add to array, increment index */


 if (index == max_words) { /* is realloc needed? */


 /* always use a temporary pointer with realloc */


 void *tmp = realloc (words, 2 * max_words * sizeof *words);


 if (!tmp) { /* validate every allocation */


 perror ("realloc-words");


 break; /* don't exit, original data still valid */


 }


 words = tmp; /* assign reallocated block to words */


 /* (optional) set all new memory to zero */


 memset (words + max_words, 0, max_words * sizeof *words);


 max_words *= 2; /* update max_words to reflect new limit */


 }


 memcpy (words[index].word, word, len + 1); /* have len */


 if (iscap) /* if cap flag set */


 words[index].cap = iscap; /* set capital flag in struct */


 words[index++].count++; /* increment count & index */


 }


 }


 fclose (fptr); /* close file */



 /*


 * Print occurrences of all words in file.


 */


 puts ("nOccurrences of all distinct words with Cap in file:");


 for (i = 0; i < index; i++) {


 if (words[i].cap) {


 strcpy (word, words[i].word);


 *word = toupper (*word);


 /*


 * %-15s prints string in 15 character width.


 * - is used to print string left align inside


 * 15 character width space.


 */


 printf("%-8d %sn", words[i].count, word);


 }


 }


 free (words);



 return 0;


}



示例使用/输出

就像上次的情况一样,你的预期输出如下所示:


$ ./bin/unique_words_exclude_top_100


Enter file path: dat/cars.txt



Occurrences of all distinct words with Cap in file:


2 Motor


8 Cars


1 German


1 Karl


2 Benz


1 Patent-motorwagen


1 Model


1 T


1 American


1 Ford


1 Company


1 Western


1 Europe


1 Electric


2 Road


1 People's


1 China


1 India



仔细看看,如果你有其他问题,请告诉我。

原作者:
106 3

word添加到words列表之前筛选出common word ,我按如下所示制作了过滤器功能:


int isCommonWord(char * word)


{


 int i = 0;


 for (i = 0; i < NUMBER_OF_STRING; i++) {


 if (strcmp(commonWords[i], word) == 0) return 1;


 }


 return 0;


}



在添加单词数组之前过滤掉单词,请参考下面我修改的代码的第二行:


if (isunique) { /* if unique, add to array, increment index */


 if (!isCommonWord(word)) {


 if (index == max_words) { /* is realloc needed? */


 /* always use a temporary pointer with realloc */


 void *tmp = realloc(words, 2 * max_words * sizeof *words);


 if (!tmp) { /* validate every allocation */


 perror("realloc-words");


 break; /* don't exit, original data still valid */


 }


 words = (words_t *)tmp; /* assign reallocated block to words */


 /* (optional) set all new memory to zero */


 memset(words + max_words, 0, max_words * sizeof *words);


 max_words *= 2; /* update max_words to reflect new limit */


 }


 memcpy(words[index].word, word, len + 1); /* have len */


 if (iscap) /* if cap flag set */


 words[index].cap = iscap; /* set capital flag in struct */


 words[index++].count++; /* increment count & index */


 }


}



我认为结果是正确的,如下所示:


Enter file path: cars.txt



Occurrences of all distinct words with Cap in file:


2 Motor


8 Cars


1 German


1 Karl


2 Benz


1 Patent-motorwagen


1 Model


1 T


1 American


1 Ford


1 Company


1 Western


1 Europe


1 Electric


2 Road


1 People's


1 China


1 India



原作者:
...