整数反转

#define _CRT_SECURE_NO_WARNINGS 1

#include<stdio.h>

#include<math.h>

int main()

{

long long a, d;

int b, c = 0;

printf("input a number:\n");

scanf_s("%lld", &a);

d = pow(2, 31);

while (1)

{

 if (a == 0) {

  printf("%d", c);

  return 0;

 }

 if (a >= (d - 1) || a <= -d) break;

 b = a % 10;

 c = c * 10 + b;

 if (c <= (-d) || c >= (d - 1)) break;

 a /= 10;

}

printf("input error ");

return 0;

}