指针go go go

/*#include<stdio.h>
main()
{
int m=1,n=2,*p=&m,*q=&n,*r;
r=p;
p=q;
q=r;
printf("%d,%d,%d,%d\n",m,n,*p,*q);
}*/


/*#include<stdio.h>
#define N 7
main()
{
int a[N]={1,2,3,4,5,6,7},i,t;
int *p=&a[0],*q=&a[N-1];
while(p<q)
{
t=*p;
*p=*q;
*q=t;
p++;
q--;
}
for(i=0;i<N;i++)
printf("%d",a[i]);
printf("\n");
}*/


/*#include<stdio.h>
main()
{
int a[]={1,3,5,7},*p=a+1;
printf("%d\n",*p++);
printf("%d\n",++*p);
printf("%d\n",(*p)++);
printf("%d\n",*++p);
}*/


/*#include<stdio.h>
swap(double *p,double *q)
{
double temp;
temp=*p;
*p=*q;
*q=temp;
}
main()
{
double a,b,*p1,*p2;
p1=&a;
p2=&b;
scanf("%lf%lf",&a,&b);
if(a<b)
swap(p1,p2);      //swap(&a,&b);
printf("max=%lf,min=%lf\n",a,b);
}*/


/*#include<stdio.h>
int fun(int x,int y,int*p)
{
int sum,sub;
sum=x+y;
sub=x-y;
*p=sub;
return sum;
}
main()
{
int a,b,m1,m2;
printf("please input two numbers:");
scanf("%d%d",&a,&b);
m1=fun(a,b,&m2);
printf("sum is %d,sub is %d\n",m1,m2);
}*/


/*#include<stdio.h>
float aver(float b[5],int n)
{
float av,s=0;
int i;
for(i=0;i<n;i++)
s=s+b[i];
av=s/5;
return av;
}
void main()
{
float a[5]={97.0,85.0,90.5,70.5,75.0},av;
av=aver(a,5);
printf("average score is %5.2f\n",av);
}*/


/*#include<stdio.h>
void fun(char *c,int d)
{
*c=*c+1;d=d+1;
printf("%c,%c,",*c,d);
}
main()
{
char b='a',a='A';
fun(&b,a);
printf("%c,%c\n",b,a);
}*/
#include<stdio.h>
#define M 6
void discount(float *p,int n,float *g)
{
int i,j=0;
for(i=0;i<M;i++)
{
p[i]=p[i]*0.85;
if(p[i]>500)
g[j++]=p[i];
}
g[j]=-1;
}
void main()
{
float p[M]={238,958,1050,599,799,198},g[M+1];
int i;
printf("打折前的价格:\n");
for(i=0;i<M;i++)
printf("%7f",p[i]);
discount(p,M,g);
printf("\n打折后的价格:\n");
for(i=0;i<M;i++)
printf("%7f",p[i]);
printf("\n打折后满500元的价格:\n");
for(i=0;g[i]>=0;i++)
printf("%7f",g[i]);
printf("\n");
}