void main()
{
    int a =5,b=3;
    int *p;
    p = &a;
    b=*P+5;
    printf("%d\n", b);
    *p = 4;
    printf("%d,%d\n",a,*p);
}

输出结果：10     4     4

之前在学校的时候就没怎么搞懂， 现在再重新学习一下，发现竟然很容易。
#include <stdio.h>
void main(){
    int a,b,c;
    int *pa,*pb,*pc;
    pa = &a,pv=&b,pc=&c;
    scanf("%d%d",pa,pb);
    printf("a=%d,b=%d\n",*pa,*pb);
    c=a+b;                 printf("c=%d\n",*pc);                                    
    *pc=a+*pb;            printf("c=%d\n",c);
    c=*pa**pb;            printf("c=%d\n",c);
    c=++*pa+(*pb)++;    printf("c=%d\n",c);
    c=(*pa)+++*pb;        printf("c=%d\n",c);
                                    printf("a=%d,b=%d\n",a,b);
}

结果：  2  3
        a=2,b=3
        c=5
        c=5
        c=6
        c=6
        c=7
        a=4,b=4