Re: [問題] 利用指標完成quicksort

看板C_and_CPP作者dendrobium (石斛蘭)時間15年前 (2010/03/22 03:15)推噓5(5推 0噓 1→)

留言6則, 6人參與討論串2/3 (看更多)

演算法本身就是錯的吧... 考慮 input[] = {3,1,2,3,4,5}; front last | | +---+---+---+---+---+---+ | 3 | 1 | 2 | 3 | 4 | 5 | +---+---+---+---+---+---+ meddle:3 因為 *last >= meddle 所以 last-- front last | | +---+---+---+---+---+---+ | 3 | 1 | 2 | 3 | 4 | 5 | +---+---+---+---+---+---+ meddle:3 again, *last >= meddle 所以 last-- front last | | +---+---+---+---+---+---+ | 3 | 1 | 2 | 3 | 4 | 5 | +---+---+---+---+---+---+ meddle:3 有等號的關係...again front last | | +---+---+---+---+---+---+ | 3 | 1 | 2 | 3 | 4 | 5 | +---+---+---+---+---+---+ meddle:3 跳出while(), swap(*front,*last); front last | | +---+---+---+---+---+---+ | 2 | 1 | 3 | 3 | 4 | 5 | +---+---+---+---+---+---+ meddle:3 接著 *front <= meddle 所以 front++ front last | | +---+---+---+---+---+---+ | 2 | 1 | 3 | 3 | 4 | 5 | +---+---+---+---+---+---+ meddle:3 直到 last front | | +---+---+---+---+---+---+ | 2 | 1 | 3 | 3 | 4 | 5 | +---+---+---+---+---+---+ meddle:3 然後 swap(*last,*front) last front | | +---+---+---+---+---+---+ | 2 | 1 | 4 | 3 | 3 | 5 | +---+---+---+---+---+---+ meddle:3 你會發現, 這個演算法根本就不正確...￣▽￣|| -- 人家可不是為了你才這樣做的哦! -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 60.198.35.85

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nowar100

03/22 11:18, , 1^F

03/22 11:18, 1^F

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dendrobium

03/22 11:20, , 2^F

03/22 11:20, 2^F

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VictorTom

03/22 11:23, , 3^F

03/22 11:23, 3^F