计算整形数组a中相邻两个元素的最大公约数，最小公倍数，其中最大公约数存入数组b中，最小公倍数存入数组c中，C语言，如何写，不用函数封装的形式写，要完整，用3种方法

方法一：

#include <stdio.h>

int gcd(int a, int b) {
    if (b == 0) {
        return a;
    }
    return gcd(b, a % b);
}

int lcm(int a, int b) {
    return a * b / gcd(a, b);
}

int main() {
    int a[] = {6, 9, 12, 15, 18};
    int n = 5;
    int b[n - 1], c[n - 1];
    for (int i = 0; i < n - 1; i++) {
        b[i] = gcd(a[i], a[i + 1]);
        c[i] = lcm(a[i], a[i + 1]);
    }
    for (int i = 0; i < n - 1; i++) {
        printf("%d ", b[i]);
    }
    printf("\n");
    for (int i = 0; i < n - 1; i++) {
        printf("%d ", c[i]);
    }
    printf("\n");
    return 0;
}

方法二：

#include <stdio.h>

int gcd(int a, int b) {
    while (b != 0) {
        int t = b;
        b = a % b;
        a = t;
    }
    return a;
}

int lcm(int a, int b) {
    return a * b / gcd(a, b);
}

int main() {
    int a[] = {6, 9, 12, 15, 18};
    int n = 5;
    int b[n - 1], c[n - 1];
    for (int i = 0; i < n - 1; i++) {
        b[i] = gcd(a[i], a[i + 1]);
        c[i] = lcm(a[i], a[i + 1]);
    }
    for (int i = 0; i < n - 1; i++) {
        printf("%d ", b[i]);
    }
    printf("\n");
    for (int i = 0; i < n - 1; i++) {
        printf("%d ", c[i]);
    }
    printf("\n");
    return 0;
}

方法三：

#include <stdio.h>

int gcd(int a, int b) {
    while (a != b) {
        if (a > b) {
            a -= b;
        } else {
            b -= a;
        }
    }
    return a;
}

int lcm(int a, int b) {
    return a * b / gcd(a, b);
}

int main() {
    int a[] = {6, 9, 12, 15, 18};
    int n = 5;
    int b[n - 1], c[n - 1];
    for (int i = 0; i < n - 1; i++) {
        b[i] = gcd(a[i], a[i + 1]);
        c[i] = lcm(a[i], a[i + 1]);
    }
    for (int i = 0; i < n - 1; i++) {
        printf("%d ", b[i]);
    }
    printf("\n");
    for (int i = 0; i < n - 1; i++) {
        printf("%d ", c[i]);
    }
    printf("\n");
    return 0;
}