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3#
發表於 2005-6-19 06:50 PM
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Originally posted by secretfj at 2005-6-19 06:37 PM:! H+ |3 y# r5 B* G
有無人知點解? b/ D# a# y3 F5 U8 n4 d8 j
Server 的Backup Code?( c, c9 ^! B5 R/ A6 T& ^
so funny, thanks a lot! % q! I/ d. w5 O, g" R9 H8 \# o) A, F5 r% v/ o: Q
好簡單, ICQ 應該係 Visual C++ 寫的 , 而係 Visual C++ 入面# B2 o* ^6 P2 P9 t4 i% \
Maximum value for a variable of type "unsigned int" 係 4294967295 (0xffffffff)
% A' O* t$ r8 w. C6 n2 w6 v% g$ Q, H個 value 過左呢個 range 就會 overflow , 佢只會理最後個32bits 數 (即係好似返返轉頭 , 循環咁) S+ i! J$ W# i( b8 B3 z& n
e.g.
* T. g4 u( Z( W) s+ W- z5 E8 k0 + 4294967295 = 4294967295 (max)3 k. T" }' E3 X) @. M' l
1 + 4294967295 = 0 + 4294967296 = 0 (because of overflow)
) E# [7 }( a6 i; p# a: A- Oand so on....
" V. { S+ e' y" w/ {- p5 V# v5 I3 s" ]8 ]: Q3 N. Q
[ Last edited by gaye on 2005-6-19 at 06:57 PM ] |
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