指針經典筆試題

筆試題一

int main()
{
    
	int a[5] = {
     1,2,3,4,5 };
	int* ptr = (int*)(&a + 1);
	printf("%d\n", *(a + 1));
	printf("%d\n", *(ptr - 1));
	return 0;
}
//程序的結果是什麼？

筆試題二

//結構體的大小是20個字節
struct Test
{
    
	int Num;
	char *pcName;
	short sDate;
	char cha[2];
	short sBa[4];
}*p;
//假設p的值為0x100000。 如下錶錶達式的值分別為多少？
int main()
{
    
	printf("%p\n", p + 0x1);
	printf("%p\n", (unsigned long)p + 0x1);
	printf("%p\n", (unsigned int*)p + 0x1);
	return 0;
}

筆試題三

int main()
{
    
  	int a[4] = {
     1, 2, 3, 4 };
  	int *ptr1 = (int *)(&a + 1);
  	int *ptr2 = (int *)((int)a + 1);
  	printf("%x\n", ptr1[-1]);
	printf("%x\n", *ptr2);
  	return 0;
}

筆試題四

#include <stdio.h>
int main()
{
    
  	int a[3][2] = {
     (0, 1), (2, 3), (4, 5) };
  	int *p;
  	p = a[0];
  	printf( "%d", p[0]);
	return 0;
}

筆試題五

int main()
{
    
  	int a[5][5];
  	int(*p)[4];
  	p = a;
  	printf("%p\n", &p[4][2] - &a[4][2]);
	printf("%d\n", &p[4][2] - &a[4][2]);
  	return 0;
}

筆試題六

int main()
{
    
	int aa[2][5] = {
     1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
	int* ptr1 = (int*)(&aa + 1);
	int* ptr2 = (int*)(*(aa + 1));
	printf("%d\n", *(ptr1 - 1));
	printf("%d\n", *(ptr2 - 1));
	return 0;
}

筆試題七

#include <stdio.h>
int main()
{
    
	char *a[] = {
    "work","at","alibaba"};
	char**pa = a;
	pa++;
	printf("%s\n", *pa);
	return 0;
}

筆試題八

int main()
{
    
	char *c[] = {
    "ENTER","NEW","POINT","FIRST"};
	char**cp[] = {
    c+3,c+2,c+1,c};
	char***cpp = cp;
	printf("%s\n", **++cpp);
	printf("%s\n", *--*++cpp+3);
	printf("%s\n", *cpp[-2]+3);
	printf("%s\n", cpp[-1][-1]+1);
	return 0;
}