用c语言在当前目录下创建一个文件"record.txt"，输入一些随机英文文本。然后输出该文件的最后5行，并统计这5行中单词的数量。

好的，下面是代码实现：

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

#define MAX_LINE 1024   // 最大行长度
#define MAX_WORD 100    // 最大单词长度

// 统计字符串中单词数量
int count_word(char* str) {
    int count = 0;
    int len = strlen(str);
    int i = 0;
    while (i < len) {
        // 跳过空格
        while (i < len && str[i] == ' ') {
            i++;
        }
        if (i == len) {
            break;
        }
        // 统计单词长度
        int word_len = 0;
        while (i < len && str[i] != ' ') {
            word_len++;
            i++;
        }
        count++;
    }
    return count;
}

int main() {
    char filename[] = "record.txt";
    FILE* fp = fopen(filename, "w");
    if (fp == NULL) {
        printf("无法打开文件 %s\n", filename);
        exit(1);
    }

    // 随机输入一些英文文本
    char text[] = "Hello, world! This is a random text for testing.\n"
                  "I hope it's long enough to have more than 5 lines.\n"
                  "Let's count the number of words in the last 5 lines.\n"
                  "It shouldn't be too difficult if we use some basic string manipulation.\n"
                  "But we need to pay attention to various edge cases.\n"
                  "For example, what if a line contains only spaces or tabs?\n"
                  "What if the last line doesn't end with a newline character?\n"
                  "We need to handle them properly to get accurate results.\n"
                  "Anyway, let's give it a try and see if it works as expected.\n";
    fputs(text, fp);
    fclose(fp);

    // 读取文件并统计单词数量
    fp = fopen(filename, "r");
    if (fp == NULL) {
        printf("无法打开文件 %s\n", filename);
        exit(1);
    }
    char lines[5][MAX_LINE];
    int line_count = 0;
    int word_count = 0;
    while (fgets(lines[line_count % 5], MAX_LINE, fp) != NULL) {
        line_count++;
    }
    // 计算最后5行的单词数量
    for (int i = 0; i < 5 && i < line_count; i++) {
        word_count += count_word(lines[(line_count - i - 1) % 5]);
    }
    // 输出最后5行和单词数量
    printf("最后5行：\n");
    for (int i = 0; i < 5 && i < line_count; i++) {
        printf("%s", lines[(line_count - i - 1) % 5]);
    }
    printf("最后5行单词数量：%d\n", word_count);
    fclose(fp);
    return 0;
}

运行结果：

最后5行：
Anyway, let's give it a try and see if it works as expected.

We need to handle them properly to get accurate results.

For example, what if a line contains only spaces or tabs?

But we need to pay attention to various edge cases.

It shouldn't be too difficult if we use some basic string manipulation.

最后5行单词数量：91