Reverse Integer

package leetcode.xuyi;

import org.junit.Test;

/**
 * Created by ethan on 2015/5/9.
 */
public class ReverseInteger {
    public int reverse(int x) {
        if(x==-2147483648 || x==2147483647)
            return 0;
        int positive_negitive = 1;
        if (x<0){
            x = -x;
            positive_negitive = -1;
        }
        long  ans = 0;
        while(x!=0){
            int tmp = x%10;
            x = x/10;
            ans = ans*10+tmp;
        }
        if (ans>2147483647 ||(positive_negitive==-1 && ans-1>2147483647)){
            return 0;
        }
        return  (int)ans*positive_negitive;
    }
    @Test
    public void test6(){
        int ans = reverse(601);
        System.out.println(ans);
    }
}