请编写程序，对一段英文文本，统计其中所有不同单词的个数，以及词频最大的前10%的单词。 所谓“单词”，是指由不超过80个单词字符组成的连续字符串，但长度超过15的单词将只截取保留前15个单词字符。而合法的“单词字符”为大小写字母、数字和下划线，其它字符均认为是单词分隔符。 输入格式: 输入给出一段非空文本，最后以符号#结尾。输入保证存在至少10个不同的单词。 输出格式: 在第一行中输出文本中所有不同单词的个数。注意“单词”不区分英文大小写，例如“PAT”和“pat”被认为是同一个单词。 随后按照词频递减的顺序，按照词频:单词的格式输出词频最大的前10%的单词。若有并列，则按递增字典序输出。使用c

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

#define MAX_WORD_LENGTH 80
#define MAX_WORD_COUNT 100000

struct Word {
    char word[MAX_WORD_LENGTH + 1];
    int count;
};

struct Word words[MAX_WORD_COUNT];

int compare(const void *a, const void *b) {
    const struct Word *x = (const struct Word *)a;
    const struct Word *y = (const struct Word *)b;
    if (x->count != y->count) {
        return y->count - x->count;
    } else {
        return strcmp(x->word, y->word);
    }
}

int main() {
    char c;
    int wordCount = 0;
    int totalCount = 0;
    char word[MAX_WORD_LENGTH + 1];
    int i, j;

    memset(words, 0, sizeof(words));

    while ((c = getchar()) != '#') {
        if (isalnum(c) || c == '_') {
            if (wordCount < MAX_WORD_LENGTH) {
                word[wordCount++] = tolower(c);
            }
        } else {
            if (wordCount > 0) {
                if (wordCount > 15) {
                    wordCount = 15;
                }
                word[wordCount] = '\0';
                int found = 0;
                for (i = 0; i < totalCount; i++) {
                    if (strcmp(words[i].word, word) == 0) {
                        words[i].count++;
                        found = 1;
                        break;
                    }
                }
                if (!found) {
                    if (totalCount < MAX_WORD_COUNT) {
                        strcpy(words[totalCount].word, word);
                        words[totalCount].count = 1;
                        totalCount++;
                    }
                }
                wordCount = 0;
            }
        }
    }

    qsort(words, totalCount, sizeof(struct Word), compare);

    printf("%d\n", totalCount);
    int topCount = totalCount / 10;
    if (topCount == 0) {
        topCount = 1;
    }
    int maxCount = words[0].count;
    for (i = 0; i < totalCount && words[i].count >= maxCount / topCount; i++) {
        printf("%d:%s\n", words[i].count, words[i].word);
    }

    return 0;
}