c语言 用指针 来判断N个数里最大直 最小直

LINUX下运行结果：
How many integers will be specified? 1
Integer #1: 2
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MAX = 2 MIN = 2
GY@localhost\ ./a.out
How many integers will be specified? 5
Integer #1: 1
Integer #2: 2
Integer #3: 3
Integer #4: 4
Integer #5: 5
--------------------------------------
MAX = 5 MIN = 1

#include <stdio.h>

int main(void)
{
int index = 0, max, min, i, *ptr;

while(! index) {
printf("How many integers will be specified? ");
scanf("%i", &index);
index = (index > 0) ? index : 0;
}

int values[index];

for (i = 0; i < index; i++) {
printf("Integer #%i: ", i + 1);
scanf("%i", &values[i]);
}

int *arrayEnd = values