Pointers and Arrays 1: simple pointer and array, The C Puzzle Book, p.53

pa1.c

#include "defs.h"

int a[]={0,1,2,3,4};

void main(){
	int i, *p;

	for( i=0; i<=4; i++ ) PR(d,a[i]);			//Pointers and Arrays 1.1
	NL;
	for( p= &a[0]; p<=&a[4]; p++ )
		PR(d,*p);								//Pointers and Arrays 1.2
	NL; NL;

	for( p= &a[0],i=1; i<=5; i++ )
		PR(d,p[i]);								//Pointers and Arrays 1.3
	NL;
	for( p=a,i=0; p+i<=a+4; p++,i++ )
		PR(d,*(p+i));							//Pointers and Arrays 1.4
	NL; NL;

	for( p=a+4; p>=a; p-- ) PR(d,*p);			//Pointers and Arrays 1.5
	NL;
	for( p=a+4,i=0; i<=4; i++ ) PR(d,p[-i]);	//Pointers and Arrays 1.6
	NL;
	for( p=a+4; p>=a; p-- ) PR(d,a[p-a]);		//Pointers and Arrays 1.7
	NL;
}

bash

$ gcc pa1.c
$ ./a.out
a[i] = 0        a[i] = 1        a[i] = 2        a[i] = 3        a[i] = 4
*p = 0  *p = 1  *p = 2  *p = 3  *p = 4

p[i] = 1        p[i] = 2        p[i] = 3        p[i] = 4        p[i] = 0
*(p+i) = 0      *(p+i) = 2      *(p+i) = 4

*p = 4  *p = 3  *p = 2  *p = 1  *p = 0
p[-i] = 4       p[-i] = 3       p[-i] = 2       p[-i] = 1       p[-i] = 0
a[p-a] = 4      a[p-a] = 3      a[p-a] = 2      a[p-a] = 1      a[p-a] = 0

本に結果が？になっているところがある。