题解 | #反转数字#

using System;
using System.Collections.Generic;


class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param x int整型
     * @return int整型
     */
    public int reverse (int x) {
        // write code here
        int nFlag = x >= 0 ? 1 : -1;
        string strX = x.ToString();
        strX = nFlag < 0 ? strX.Replace("-", "") : strX;
        string strRX = string.Empty;
        for (int nIndex = 0; nIndex < strX.Length; nIndex++)
            strRX = strX[nIndex].ToString() + strRX;
        int nRtn = 0;
        string strLQ = (Math.Pow(2, 31)).ToString();
        string strRQ = (Math.Pow(2, 31) - 1).ToString();
        bool bL = strRX.Length > strLQ.Length || ((strRX.Length == strLQ.Length) &&
                  string.Compare(strRX, strLQ) > 0);
        bool bR = strRX.Length > strRQ.Length || ((strRX.Length == strRQ.Length) &&
                  string.Compare(strRX, strRQ) > 0);
        if (bL || bR)
            return 0;
        for (int nIndex = strX.Length - 1; nIndex >= 0; nIndex--)
            nRtn +=  Convert.ToInt32(strX[nIndex].ToString()) * (int)Math.Pow(10, nIndex);
        return nFlag * nRtn;
    }
}