[์•Œ๊ณ ๋ฆฌ์ฆ˜] ๊ณผ์ œ 3. Tony Hoare :: QuickSort ๋…ผ๋ฌธ ํ•ด์„ํ•˜๊ธฐ
์ปดํ“จํ„ฐ๊ณผํ•™ (CS)/Algorithm 2020. 3. 26. 16:56

QuickSort ๋…ผ๋ฌธ brief Part One: Theory ์ด sorting์€ ๋‘ ๊ฐœ์˜ ๊ฐ„๋‹จํ•œ ๋ณด์กฐ๋ฌธ์ œ๋กœ ๋‚˜๋‰˜์–ด ํ•ด๊ฒฐ๋  ์ˆ˜ ์žˆ๋Š”๋ฐ, ๊ฐ ๋ฌธ์ œ๋Š” ์ด๋ฏธ ์•Œ๋ ค์ง„ ๋ฐฉ์‹์œผ๋กœ ํ’€ ์ˆ˜ ์žˆ๋‹ค. Partition : key๊ฐ’์„ dividing line์— ๋”ฐ๋ผ ์œ„ ์•„๋ž˜๋กœ ๋‚˜๋ˆ„์–ด ์ด๋ถ„ํ•˜๋Š” ๊ฒƒ ์‹ค์ œ๋กœ ์ด dividing line์€ ํ”์น˜ ์•Š๊ณ , ์žˆ๋‹ค ํ• ์ง€๋ผ๋„ ์ฐพ๊ธฐ ํž˜๋“ ๋ฐ dividing line์ด ์กด์žฌํ•˜๊ณ  ๊ทธ๊ฒƒ์˜ ์œ„์น˜๋งŒ ์•ˆ๋‹ค๋ฉด item๋“ค์„ ์žฌ์ •๋ ฌํ•˜๊ธฐ๋Š” ์‰ฌ์›Œ์ง„๋‹ค. partition ๊ณผ์ • ์ •๋ ฌ๋˜์–ด์•ผํ•˜๋Š” ์•„์ดํ…œ์˜ ํ‚ค ์ค‘ ํŠน์ • ํ‚ค๋ฅผ ๊ณ ๋ฅธ๋‹ค. ์ด ํ‚ค๋Š” bound ๋ผ ๋ถˆ๋ฆฐ๋‹ค. dividing line ์•„๋ž˜์—๋Š” bound๋ณด๋‹ค ์ž‘๊ฑฐ๋‚˜ ๊ฐ™์€ key๊ฐ’์ด, ์œ„์ชฝ์—๋Š” ํฐ key ๊ฐ’์ด ์˜ค๊ฒŒ ํ•œ๋‹ค. dividing line์˜ ์œ„์น˜๋Š” ๋ฏธ๋ฆฌ ์•Œ ํ•„์š”..