#include <stdio.h>
#include <math.h>
#include <string.h>
void main() {
float a[20], *p = a;
int n;
a[1] = 2.1;
printf("%f",p[1]);
puts("你想輸入幾個數(<=20)");
scanf_s("%d", &n);
for (int i = 0; i < n; i++)
scanf_s("%f",p+i);//為什麼這裡不能用 p[i]? 书上明明说可以~!~
for (int i = n-1; i > -1; i--)
printf("%f ", *(p + i));
printf("\n");
}