判断回文数

int checkNum(int a)
{
int sum = 1;
while (a / 10 > 0)
{
sum++;
a /= 10;
}
return sum;
}

void main()
{
int a,b;
scanf(“%d”, &a);
getchar();
b=checkNum(a);
switch (b)
{
case 1:
printf(“不是回文数”);
break;
case 2:
if (a % 10 == a / 10)
{
printf(“是回文数”);
}
else
{
printf(“是回文数”);
}
case 3:
if (a % 10 == a / 100)
{
printf(“是回文数”);
}
else
{
printf(“是回文数”);
}
case 4:
if ((a % 10 == a / 1000) && (a /100 % 10 ==a / 10 %10))
{
printf(“是回文数”);
}
else
{
printf(“是回文数”);
}
case 5:
if ((a % 10 == a / 10000) && (a / 1000 % 10 == a / 10 % 10))
{
printf(“是回文数”);
}
else
{
printf(“是回文数”);
}
case 6:
if ((a % 10 == a / 100000) && (a / 10000 % 10 == a / 10 % 10) && (a/100%10 == a/1000%10))
{
printf(“是回文数”);
}
else
{
printf(“是回文数”);
}
}
}