欧拉计划·第四题

题目4：找出由两个三位数乘积构成的回文。

源代码

STDMETHODIMP COuLa::Test4(int iMaxNumber)
{
	// TODO: 在此添加实现代码
	int outputNumber = 0;
	int iMaxOutputNumber = 0;
	for(int i = iMaxNumber/10; i<iMaxNumber; i++)
	{
		for(int j = i; j<iMaxNumber; j++)
		{
			outputNumber = j*i;
			int iFirstNumber = outputNumber;
			int iSecondNumber = iFirstNumber;
			int iThirdNumber = iSecondNumber;
			while(iFirstNumber > 9)
			{
				iThirdNumber = iSecondNumber%10;
				iSecondNumber = iFirstNumber%10;
				iFirstNumber = iFirstNumber/10;
			}
			//printf("iFirstNumber is %d.\n", iFirstNumber);
			if(outputNumber%10 == iFirstNumber && (outputNumber/10%10) == iSecondNumber && (outputNumber/100%10) == iThirdNumber)
			{
				if(iMaxOutputNumber < outputNumber) iMaxOutputNumber = outputNumber;
			}
		}
	}
	printf("The Test 4 Number is %d.\n",iMaxOutputNumber);
	return S_OK;
}

函数调用

#define TEST4_NUMBER 1000
IOula->Test4(TEST4_NUMBER);

输出

The Test 4 Number is 906609.