c - 找到出现次数较多的字符串(单词)

Question

我必须给一个数字x，并写x个字符串(单词)。我必须找到写得最多的那一篇。它可以工作，但是当我尝试从文件中读取它时，却没有。例如，如果我执行 a.out''<'file 并且文件如下:

1. 5
2. 你好
3. 是
4. 世界
5. 你好
6. 好的

所有这些都在不同的行中，每个字符串在不同的行中它都可以工作，并且我打印你好，但是如果很多字符串像文本一样在一行中，它就不会工作(hello yes word hello e.t.c...

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

int main(void)
{
    char **str;
    int n,i,j,y;
    int count=0;
    printf("Give a nubmer : \n");
    scanf("%d", &n);
    str = (char **)malloc(n *(sizeof(50)));
    for(i=0; i<n+1; i++)
            str[i] = (char *)malloc(50);
    printf("Give n strings : \n");
    for(i=0; i<n+1; i++)
    {
            gets(str[i]);
    }
    for(i=0; i<n+1; i++)
    {
            for (j=i+1;j<n+1;j++)
            {
                    if(strcmp(str[i],str[j])==0)
                    {
                            count++;
                    //      i++;
                            y=i;
                    }
            }
    }
    printf("\n%s\n",str[y]);
}

这是我使用 gets 而不是 fgets 的问题吗？

Answer 1

考虑以下因素:

#define NUM_STRINGS (10)

int strListCompare(const void *p1, const void *p2)
{
    const char **str1 = p1;
    const char **str2 = p2;
    return strcmp(*str1, *str2);
}

int main(void)
{
    char *strList[NUM_STRINGS] = {
                                     "dog", "cat", "cat", "bat", "cat", 
                                     "cat", "dog", "bat", "dog", "bat"
                                 };

    qsort(strList, NUM_STRINGS, sizeof(char *), strListCompare);

    char *curStr = strList[0], *maxStr = strList[0];
    int curCount = 0, maxCount = 0;

    for(int i = 0; i < (NUM_STRINGS - 1); i++)
    {
        curCount++;

        if((strcmp(strList[i], strList[i + 1]) != 0) && (curCount > maxCount))
        {
            maxCount = curCount;
            maxStr = strList[i];
            curCount = 0;
        }
    }

    printf("The winner! \"%s\" (%d occurrences)\n", maxStr, maxCount);
    return 0;
}

执行上述程序会产生以下输出:

The winner! "cat" (4 occurrences)

这是逻辑:

At first, strList is not sorted. I sort it to aid in determining the string that occurs the most. Before I scan strList, I assume the first element will be the most occurring string. Now, I scan strList and count occurrences. If the next string is the same as the current string, I increment curCount. As soon as the next string is not the same as the current string, I compare curCount to maxCount. If curCount is greater than maxCount, I've found a new string that occurs the most often. I set curCount and the current string to maxCount and maxStr respectively. When the loop ends, maxCount and maxStr will the have the string that occurs the most.