作者castin (调整自己)
看板TransCSI
标题Re: [问题]考古题
时间Sun Jun 28 09:38:37 2009
※ 引述《bill790602 (REBORN)》之铭言:
: 1.what is the Excess_128 representation of 5?
: (a)00000101(b)10000100(c)10000101(d)10000001
超128就是加128...
(5+128)10=(10000101)2
答案为c
: 2.Change the decimal number-124 to an 8-bittwo's complement integer
(-124)10用8bits,2的补数来表示
(124)10=(1111100)2 转2的补数为(0000100)2
答案为10000100
: 3.An alogorithm of complexity O(n log n)is not as efficient as one of order
: (a)O(logˇ2n)(b)O(n^2 )(c)O(2^n )(d)O(n√n)(e)n^(log_(2^n ) )
答案为d 这...是数学问题吗...
: 4.Can you draw a binary tree from the following prefix and infix traversal
: order?If yes,draw the tree.If not,state your reason
: Prefix:D B A C I E H
: Infix:A B H C D E I
Prefix的D在B的左子树~~
Infix的D在A的右子树阶层中~~
应该是画不出来吧....
: 5.We have an integer array foo[3][7]in a C program. Assume that each integer
: is Stored in two bytes.The array is stored in row-major order .If foo[0][0] is
: stored at 0x200,where is foo[2][3]?
0x200是(200)16...
f00[2][3]=f[0][0]+[(2-0)*7+(3-0)]*2
=200+(34)10=200+22=222
答案为0x222
//解释到一半发现我写错了XD....以上更正
阵列的储存方式有两种~~row-major和column-major
row-major的内部结构就是
xxxxxxx
xxxxxxx ->一列一列存,存完一列再存下一列
xxx'x'
column-major则是
xxx
xxx
xxx
xxx
xx ->一行一行存,存完一行再存下一行
xx
xx
第一个x是f[0][0] 它的位址是0x200(16进制的200)
问你f[2][3]就是row-major的'x'的位址
那先算前面几个x-->2*7+3=17
一个x的大小是2byte-->17*2=34 转16进制=22
0x200+22=0x222
: 6x.What are the three main features of Object-Oriented
: Programming Language?
封装、继承、多型
: 麻烦各位大大了~
: 小弟遇到瓶颈ˊˋ
请前辈多多指教!!!!^-^
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◆ From: 125.230.19.161
1F:推 bill790602:第五题能稍微解释吗?看不懂ˊˋ 06/28 09:54
※ 编辑: castin 来自: 125.230.19.161 (06/28 11:01)
2F:→ bill790602:谢谢大大~ 06/28 15:40