题目描述

请编写函数，对小数进行四舍五入。
double Round(double x, int d);
说明：x 为任意实数，d 为小位位数。函数值为将 x 其四舍五入后得到的保留 d 位小数的实数。

裁判程序

#include <stdio.h>
#include <math.h>

int IsOdd(int number);
int IsEven(int number);
double Power(double x, int n);
double Round(double x, int d);

int main()
{
    
    
    double x;
    int d;
    scanf("%lg%d", &x, &d);
    printf("%.15g\n", Round(x, d));
    return 0;
}

...(略)...

/* 你提交的代码将被嵌在这里 */

输入样例1:

25.836 2

输出样例1:

25.84

输入样例2:

-18.274 2

输出样例2:

-18.27

源代码

double Round(double x, int d)
{
    
    
    int flag=0,i;
    double muti,current;
    long long int part;
    if(x<0)
    {
    
    
        current=-x;
        flag=1;
    }
    else
        current=x;
    if(d>=0)
    {
    
    
        current=current*Power(10.0,d+1)+5;
        part =current/10;
        current=part;
        current=current/(Power(10.0,d));  
        if(flag==1)
            printf("-");
        return current;
        
    }
    if(d<0)
    {
    
    
        part=current;
        part=part/(Power(10.0,-d-1))+5;
        part=part/10;
        part=part*Power(10.0,-d);
        if(flag==1)
            printf("-");
        return part;
    }
}