while循环的问题，有没有高手指点下？

Question

int main(void)
{
int x, a[16], i = 0, k, y;
scanf_s("%d",&x);
y = x;
while (y != 0)
{
a[i] = y % 2;
y = y / 2;
i++;
}
printf("%d = ",x);
for (k = i - 1; k >= 0; k--)
printf("%1d",a[k]);
printf("\n");
getchar();
getchar();
return 0;
}

while循环过后为什么i=5？

当x=y=26

Answer 1

跑完第一次循环：a[0] = 0, y = 13, i = 1
跑完第二次循环：a[1] = 1, y = 6, i = 2
跑完第三次循环：a[2] = 0, y = 3, i = 3
跑完第四次循环：a[3] = 1, y = 1, i = 4
跑完第五次循环：a[4] = 0, y = 0, i = 5
此时y=0，不满足条件，退出while循环