[code=c]
请填写代码
[/code]
#include <stdio.h>
void main(){
    int x;
    double y,z,p;
    printf("input the number of the people\n");
    scanf("%d",&x);
scanf("%lf",&y);
    z = (y-3.5*x)/(3.5*x);
/*    if(z<=0)
        p = y*3.7;
else     if(z<=0.2)
        p = 3.5*x*3.7+3.7*2*(y-3.5*x);
    else if(z<=0.4)
        p =3.5*x*3.7+3.7*2*3.5*x*0.2+3.7*3*(y-3.5*x*(1+0.2));
else
        p =3.5*x*3.7+3.7*2*3.5*x*0.2+3.7*3*0.2*3.5*x+3.7*4*(y-3.5*x*(1+0.4));
        */

         if(z<=0)
        p = y*3.7;
     if(0<z<=0.2)
        p = 3.5*x*3.7+3.7*2*(y-3.5*x);
     if(0.2<z<=0.4)
        p =3.5*x*3.7+3.7*2*3.5*x*0.2+3.7*3*(y-3.5*x*(1+0.2));
if(z>0.4)
        p =3.5*x*3.7+3.7*2*3.5*x*0.2+3.7*3*0.2*3.5*x+3.7*4*(y-3.5*x*(1+0.4));
    /*if(z<=0)
        p = y*3.7;
     if(0<z&&z<=0.2)
        p = 3.5*x*3.7+3.7*2*(y-3.5*x);
     if(0.2<z&&z<=0.4)
        p =3.5*x*3.7+3.7*2*3.5*x*0.2+3.7*3*(y-3.5*x*(1+0.2));
if(z>0.4)
        p =3.5*x*3.7+3.7*2*3.5*x*0.2+3.7*3*0.2*3.5*x+3.7*4*(y-3.5*x*(1+0.4));*/

printf("is %lf\n",p);
}
其中if(0<z&&z<=0.2)与if(0<z<=0.2)有什么不同？