调试的时候一直无限循环，时间超限，想知道哪里写错了？

#include
int main()
{
int t, n;
int a,b,c,d;
scanf_s("%d", &t);
for (t = t; t > 0; t--)
{
scanf_s("%d", &n);
if (n >= 6 && n <= 80)
{
for (a = n - 1; a > 0; a--)
{
printf("-");
}
printf("\n");
printf("\");
for (b = a - 2; b > 0; b--)
{
printf(" ");
}
printf("/\n");
c = b - 2;
d = 1;
while (c != 3)
{
for (d = d; d > 0; d--)
{
printf(" ");
}
printf("\");
for (c = c; c > 0; c--)
{
printf("*");
}
printf("/\n");
c = c - 2;
d = d + 1;
}
a = 0; b = 0; c = 0; d = 0;
}
}

调试的时候一直无限循环/
想知道是哪里写错了

while (c != 3)
{
for (d = d; d > 0; d--)
{
printf(" ");
}
printf("");
for (c = c; c > 0; c--)
{
printf("*");
}
printf("/\n");
c = c - 2;
d = d + 1;
}
c的原因