c语言设计中，如何不用数组来判断整数数列是否有序

Question

判断是否有序，不能用数组的方法来判断 输入整数数列长度n，然后输入数列内容，输出有序无序

Answer 1

#include<stdio.h>

int main() {
    int n, x, y;
    printf("Please enter n: ");
    scanf("%d", &n);
    printf("Please enter %d numbers:\n", n);
    if (n == 1) 
    {
        printf("Only 1 number, in order any way.");
    }
    else
    {
        scanf("%d%d", &x, &y);
        int ascending = x <= y ? 1 : 0;
        x = y;
        
        for (int i = 2; i < n; ++i)
        {
            scanf("%d", &y);
            if (ascending ^ (x < y))
            {
                printf("Not in order.");
                return 0;
            }
            x = y;
        }
        if (ascending)
        {
            printf("in ascending order.");
        }
        else 
        {
            printf("in descending order.");
        }
    }

    return 0;
}

// Output
Please enter n: 9
Please enter 9 numbers:
1 2 3 4 5 6 7 8 9
in ascending order.


Please enter n: 10
Please enter 10 numbers:
9 8 7 6 5 4 3 2 1 0
in descending order.

Please enter n: 5
Please enter 5 numbers:
1 5 9 3 2
Not in order.

Please enter n: 3     
Please enter 3 numbers:
1 3 2
Not in order.


Please enter n: 2
Please enter 2 numbers:
1 2
in ascending order.