Reverse Integer 解题报告

/**
*
* @author ganyee Reverse digits of an integer. Example1: x = 123, return 321
*         Example2: x = -123, return -321
*/
public class ReverseInteger {

public static void main(String[] args) {
// TODO Auto-generated method stub
// System.out.println(reverse(10000000));
// System.out.println(reverse(1534236469));
System.out.println(reverse(-2147483648));
System.out.println(reverse(9646351));
}

public static int reverse(int x) {
int flag = 0;
long newX = x;

//输入时判断是否溢出
if (newX < 0) {
newX = Math.abs(newX);
flag = 1;
} else {
newX = x;
}
if (newX == 0 || newX > Integer.MAX_VALUE)
return 0;

String str = Long.toString(newX);
StringBuffer stringBuffer = new StringBuffer(str);
str = stringBuffer.reverse().toString();

//输出是判断是否发生溢出
if (Long.parseLong(str) > Integer.MAX_VALUE)
return 0;
System.out.println(str);
while (str.startsWith("0")) {
str = str.substring(1);
}

if (flag == 1) {

return (0 - Integer.parseInt(str));
} else {
return Integer.parseInt(str);
}
}

}