请问这个怎么运用数列的知识写出来

Question

请问这个怎么运用c语言数列的知识写出来？麻烦详细解释一下谢谢！

Answer 1

#include <stdio.h>
 
int main()
{
    int n, flag = 1;
    scanf("%d", &n);
    int arr[110];
    while (1)
    {
        int n1 = 0;
        while (1)
        {
            scanf("%d", &arr[n1]);
            if (arr[n1] == -1) goto endp;
            if (arr[n1] == 0) break;
            n1++;
        }
        int cnt = 0;
        for (int i = 0; i < n1 - 1; i++)
        {
            for (int j = i + 1; j < n1; j++)
                if (arr[i] * n == arr[j])
                    cnt++;
        }
        if (!flag) printf("\n");
        printf("%d", cnt);
        flag = 0;
    }
endp:
    return 0;
}