C#中的圆积分数

Question

我一直在搜索这个问题几个小时,但我找不到答案所以我问它:

我正在寻找一种方法或一些四舍五入25,599,999至25,000,000或25,599,999到30,000,000:

 int num1 = 25599999;
 Console.WriteLine(RoundDown(num1, 6 /* This is the places (numbers from end that must be 0) */)) // Should return 25,000,000;

或者向上:

 int num1 = 25599999;
 Console.WriteLine(RoundUp(num1, 6 /* This is the places (numbers from end that must be 0) */)) // Should return 30,000,000;

注意:我不是在寻找一种舍入十进制数的方法.

Answer 1

int RoundDown(int num, int digitsToRound)
{
    double tmp = num / Math.Pow(10, digitsToRound);

    return (int)(Math.Floor(tmp) * Math.Pow(10, digitsToRound));
}

int RoundUp(int num, int digitsToRound)
{
    double tmp = num / Math.Pow(10, (digitsToRound + 1)) + 1;

    return (int)(Math.Floor(tmp) * Math.Pow(10, (digitsToRound + 1)));
}