编码一个计算两个整数间的素数个数的代码

为了编写一个计算两个整数之间（包括这两个数本身）素数个数的程序，你可以使用Sieve of Eratosthenes（埃拉托斯特尼筛法）来预生成一定范围内的所有素数，然后遍历指定区间找出其中的素数。以下是使用C语言的一个例子：

#include <stdio.h>
#include <stdbool.h>
#define MAX_PRIME 10000

// Function to generate primes using Sieve of Eratosthenes
bool* sieve_of_eratosthenes(int limit) {
    bool prime[MAX_PRIME + 1];
    for (int i = 2; i <= MAX_PRIME; i++)
        prime[i] = true;

    for (int p = 2; p * p <= MAX_PRIME; p++) {
        if (prime[p]) {
            for (int i = p * p; i <= MAX_PRIME; i += p)
                prime[i] = false;
        }
    }

    return prime;
}

// Function to count primes between two numbers
int count_primes_between(int start, int end, bool* prime) {
    int count = 0;
    for (int i = start; i <= end; i++) {
        if (prime[i])
            count++;
    }
    return count;
}

int main() {
    int start_num, end_num;
    printf("请输入两个整数，之间将会统计素数个数：\n");
    scanf("%d%d", &start_num, &end_num);

    if (start_num > end_num) {
        int temp = start_num;
        start_num = end_num;
        end_num = temp;
        printf("交换输入顺序：现在从 %d 到 %d 寻找素数。\n", start_num, end_num);
    }

    bool* primes = sieve_of_eratosthenes(end_num);
    int result = count_primes_between(start_num, end_num, primes);
    free(primes); // 释放内存

    printf("在%d到%d之间的素数个数为：%d\n", start_num, end_num, result);

    return 0;
}