Intel和微软同时出现的C语言面试题 =9lrPQ]w
#pragma pack(8) 3c"$@W:>
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struct s1{ _::q
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short a; =?*6lS}gy
long b; &nc0stuL
}; cmzu
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struct s2{ D['z/r6F
char c; SG&VZY
s1 d; nPW?DbH +
long long e; eYER"E
}; 'E4`qq
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#pragma pack() Qg7rkRia
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问 &
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1.sizeof(s2) = ? ]vyu!
2.s2的s1中的a后面空了几个字节接着是b? X`[P11`
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如果您知道答案请在讨论中写出,以下是部份网友的答案,供参考: %{fa
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网友rwxybh(行云)的答案: RGeM.
内存布局是 :QndeUw
1*** 11** GTj=R$%09
1111 **** LDj'L~H
1111 1111
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所以答案就是24和3 I^M%+\
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下面是一个测试的程序,试一试就知道了,我用的是VC2005 SWAggW)
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#pragma pack(8) 5/v,|
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struct s1{ YL )epi^
short a; // 2 BYtes F-\Swbx+
long b; // 4 Bytes AoaRlk-#
}; E&\dr;{7
struct s2{ 0{ZYYB&"~J
char c; // 1 Byte BFU6?\r
s1 d; // 8 Bytes g>lJZD@
long long e; // 8 Bytes hi{#HXa
}; c)d*[OI8
// 1*** 11** .4M8
// 1111 **** )HrFWI'Y
// 1111 1111 Ub0hISA
// !)jw o=l}J
^w0V{qF{
// 00 01 02 03 04 05 06 07 61Z#;2]
// 00 01 02 03 04 05 06 07 (,5oqU9s@
// 00 01 02 03 04 05 06 07 O'6zV"<P
// xiu?BP?V
#pragma pack() >&@hm4
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int main(int argc, char* argv[]) bv.DW,l%'
{ QT1(= wK3
s2 a; ugtzF
char *p = (char *)&a; }Yi)r*LI3
for(int i=0;i<24;++i) dmq<vVxC
p = (char)(i%8); t SST.o3
printf("%d\n",sizeof(a)); C~do*rnM^
printf("c=0x%lx\n",a.c); p!+7F\
printf("d.a=0x%x\n",a.d.a); S?X2MX
printf("d.b=0x%x\n",a.d.b); e&Z\hZBb
printf("e=0x%llx\n",a.e); T;cyU9
return 0; Wq bfZx
} ND w+bR-
结果: 59?@55
24 4?#0fK
c=0x0 u!k]Q#2ZR
d.a=0x504 BrW1:2w
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d.b=0x3020100 ;2o+|U@
e=0x706050403020100 @/S6P-4
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