剑指Offer面试题：10.数值的整数次方

#include <math.h>

bool Equal(double num1, double num2)
{
    if (num1 - num2 > -0.0000001 &&
        num1 - num2 < 0.0000001)
    {
        return true;
    }
    else
    {
        return false;
    }
}

// 基数为base为double类型，exponent为整数
double Power(double base, int exponent) throw(char *)
{
    // 当底数为0且指数为负数时抛出异常
    if (Equal(base,0.0) && (exponent < 0))
    {
        throw "base must be positive!";
    }
    double dbResult = 1.0;
    if (exponent >= 1)
    {
        for (int i = 0; i < exponent; i ++)
        {
            dbResult *= base;
        }
    }
    else if (exponent < 0)
    {
        for (int j = 0; j < abs(exponent); j ++)
        {
            dbResult *= base;
        }
        dbResult = 1/dbResult;
    }
    else if(exponent == 0)
    {
        dbResult = 1;
    }
    return dbResult;
}

void main()
{
    try
    {
        cout << Power(0,1) << endl;
        cout << Power(2, 3) << endl;
        cout << Power(-2, 3) << endl;
        cout << Power(2, -3) << endl;
        cout << Power(2, 0) << endl;
        cout << Power(0,-1) << endl;
    }
    catch (char *pError)
    {
        cout << pError << endl;
    }
    
    return;
}