求给出一个小数，得出与0, 0.25, 0.5, 0,75,1这组数种那个差值最小

#include <stdio.h>
#include <math.h>
#include <stdlib.h>
int main（)
{
    double a[8]={0.0,0.25,0.5,0.75,1.0};
    double b,min = 1<<16;
    int i,j,k=0;
    scanf（"%lf",&b);
    for（i=0;i<5;i++)
    {
        if（min>fabs（b-a[i])) 
        {
            min = fabs（b-a[i]);  
            k=i;   
        }      
    }   
    printf（"%lf\n",a[k]);
    system（"pause");
}

float a[5];
a[0] = 0 * 0.25;
a[1] = 1 * 0.25;
a[2] = 2 * 0.25;
a[3] = 3 * 0.25;
a[4] = 4 * 0.25;