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[se6816] WEEK 14 Solutions#2336

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TonyKim9401 merged 3 commits intoDaleStudy:mainfrom
se6816:main
Feb 14, 2026
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[se6816] WEEK 14 Solutions#2336
TonyKim9401 merged 3 commits intoDaleStudy:mainfrom
se6816:main

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@se6816 se6816 commented Feb 14, 2026

๋‹ต์•ˆ ์ œ์ถœ ๋ฌธ์ œ

์ž‘์„ฑ์ž ์ฒดํฌ ๋ฆฌ์ŠคํŠธ

  • Projects์˜ ์˜ค๋ฅธ์ชฝ ๋ฒ„ํŠผ(โ–ผ)์„ ๋ˆŒ๋Ÿฌ ํ™•์žฅํ•œ ๋’ค, Week๋ฅผ ํ˜„์žฌ ์ฃผ์ฐจ๋กœ ์„ค์ •ํ•ด์ฃผ์„ธ์š”.
  • ๋ฌธ์ œ๋ฅผ ๋ชจ๋‘ ํ‘ธ์‹œ๋ฉด ํ”„๋กœ์ ํŠธ์—์„œ Status๋ฅผ In Review๋กœ ์„ค์ •ํ•ด์ฃผ์„ธ์š”.
  • ์ฝ”๋“œ ๊ฒ€ํ† ์ž 1๋ถ„ ์ด์ƒ์œผ๋กœ๋ถ€ํ„ฐ ์Šน์ธ์„ ๋ฐ›์œผ์…จ๋‹ค๋ฉด PR์„ ๋ณ‘ํ•ฉํ•ด์ฃผ์„ธ์š”.

๊ฒ€ํ† ์ž ์ฒดํฌ ๋ฆฌ์ŠคํŠธ

Important

๋ณธ์ธ ๋‹ต์•ˆ ์ œ์ถœ ๋ฟ๋งŒ ์•„๋‹ˆ๋ผ ๋‹ค๋ฅธ ๋ถ„ PR ํ•˜๋‚˜ ์ด์ƒ์„ ๋ฐ˜๋“œ์‹œ ๊ฒ€ํ† ๋ฅผ ํ•ด์ฃผ์…”์•ผ ํ•ฉ๋‹ˆ๋‹ค!

  • ๋ฐ”๋กœ ์ด์ „์— ์˜ฌ๋ผ์˜จ PR์— ๋ณธ์ธ์„ ์ฝ”๋“œ ๋ฆฌ๋ทฐ์–ด๋กœ ์ถ”๊ฐ€ํ•ด์ฃผ์„ธ์š”.
  • ๋ณธ์ธ์ด ๊ฒ€ํ† ํ•ด์•ผํ•˜๋Š” PR์˜ ๋‹ต์•ˆ ์ฝ”๋“œ์— ํ”ผ๋“œ๋ฐฑ์„ ์ฃผ์„ธ์š”.
  • ํ† ์š”์ผ ์ „๊นŒ์ง€ PR์„ ๋ณ‘ํ•ฉํ•  ์ˆ˜ ์žˆ๋„๋ก ์Šน์ธํ•ด์ฃผ์„ธ์š”.

@TonyKim9401
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@DaleStudy ๋ฆฌ๋ทฐํ•ด์ค˜

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dalestudy bot commented Feb 14, 2026

๋จผ์ € ์—ฌ๋Ÿฌ ๋ฌธ์ œ๋ฅผ ํ•œ PR์— ๊น”๋”ํ•˜๊ฒŒ ์ •๋ฆฌํ•˜์‹  ์ , ๊ทธ๋ฆฌ๊ณ  ๊ฐ๊ฐ์˜ ํ•ด๊ฒฐ์ฑ…์ด ์ž˜ ๊ตฌํ˜„๋˜์–ด ์žˆ์–ด ๋งค์šฐ ์ธ์ƒ์ ์ž…๋‹ˆ๋‹ค! ์•„๋ž˜๋Š” ๊ฐ ํŒŒ์ผ๋ณ„ ํ”ผ๋“œ๋ฐฑ๊ณผ ํ•จ๊ป˜ ์ „๋ฐ˜์ ์ธ ์ œ์–ธ์ž…๋‹ˆ๋‹ค.

1. binary-tree-level-order-traversal/se6816.java

  • ์žฅ์ : DFS๋ฅผ ์ด์šฉํ•œ ๋ ˆ๋ฒจ ์ˆœํšŒ ๊ตฌํ˜„์ด ๊น”๋”ํ•˜๋ฉฐ, list.size() == depth ์กฐ๊ฑด์œผ๋กœ ๋ ˆ๋ฒจ๋ณ„ ๋ฆฌ์ŠคํŠธ ์ƒ์„ฑ์ด ์ ์ ˆํ•ฉ๋‹ˆ๋‹ค.
  • ์ถ”์ฒœ: ์‹œ๊ฐ„/๊ณต๊ฐ„ ๋ณต์žก๋„(TC: O(n), SC: O(n))๋ฅผ ์ฃผ์„์œผ๋กœ ๋ช…์‹œํ•˜๋ฉด ๋” ์ข‹๊ฒ ์Šต๋‹ˆ๋‹ค. DFS๋Š” ๋…ธ๋“œ ์ˆ˜ n์— ๋Œ€ํ•ด ์„ ํ˜•์ด๋‹ˆ ์ด ์ •๋„๋ฉด ์ถฉ๋ถ„ํžˆ ์•Œ ์ˆ˜ ์žˆ๊ฒ ๋„ค์š”.
  • ๊ฐ€๋…์„ฑ: ๋ณ€์ˆ˜๋ช…(dest)์ด ์ง๊ด€์ ์ด๋ฉฐ, ์ฝ”๋“œ๋„ ๊น”๋”ํ•ฉ๋‹ˆ๋‹ค.

2. counting-bits/se6816.java

  • ์žฅ์ : Integer.bitCount() ํ™œ์šฉ์ด ๊ฐ„๋‹จํ•˜๊ณ  ํšจ์œจ์ ์ž…๋‹ˆ๋‹ค.
  • ์ถ”์ฒœ: ์ด ๋ฐฉ๋ฒ•์€ ์ตœ์ ์ด๊ธด ํ•˜์ง€๋งŒ, ๋” ๋น ๋ฅธ ๋ฐฉ๋ฒ•์œผ๋กœ ๋™์  ํ”„๋กœ๊ทธ๋ž˜๋ฐ์„ ํ™œ์šฉํ•˜๋Š” ๊ฒƒ๋„ ๊ณ ๋ คํ•  ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค. ์˜ˆ๋ฅผ ๋“ค์–ด, dp[i] = dp[i >> 1] + (i & 1) ๋ฐฉ์‹์ด ๋” ๋น ๋ฅธ ๊ฒฝ์šฐ๊ฐ€ ๋งŽ์•„ ์ถ”์ฒœ๋“œ๋ฆฝ๋‹ˆ๋‹ค.
  • ๋ณต์žก๋„: ํ˜„์žฌ ๊ตฌํ˜„์€ TC: O(n), SC: O(n)์œผ๋กœ ์ ์ ˆํ•˜๋ฉฐ ์ •ํ™•ํ•ฉ๋‹ˆ๋‹ค.

3. house-robber-ii/se6816.java

  • ์žฅ์ : ๋‘ ๊ฒฝ์šฐ(์ฒซ ์ง‘ ํ„ด/๋น„ํ„ด)๋ฅผ ๋‚˜๋ˆ ์„œ ํ•ด๊ฒฐํ•˜๋Š” ๋ฐฉ์‹์ด ๊น”๋”ํ•ฉ๋‹ˆ๋‹ค.
  • ์ถ”์ฒœ: ๋‘ ๊ฒฝ์šฐ๋ฅผ ์ฒ˜๋ฆฌํ•˜๋Š” ๋กœ์ง์€ ์ž˜ ์ž‘์„ฑ๋์œผ๋‚˜, ์ค‘๋ณต๋˜๋Š” ์ฝ”๋“œ๋ฅผ ํ•จ์ˆ˜๋กœ ๋ฆฌํŒฉํ† ๋งํ•˜๋ฉด ๊ฐ€๋…์„ฑ์ด ๋” ์ข‹์•„์งˆ ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค. ์˜ˆ๋ฅผ ๋“ค์–ด, robLinear๋ผ๋Š” ํ•จ์ˆ˜๋กœ ๋งŒ๋“ค์–ด ์žฌ์‚ฌ์šฉ ๊ฐ€๋Šฅํ•˜๊ฒŒ ํ•˜๋ฉด ์œ ์ง€๋ณด์ˆ˜๋„ ์šฉ์ดํ•˜๊ฒ ์–ด์š”.
  • ๋ณต์žก๋„: ์‹œ๊ฐ„๋ณต์žก๋„๋Š” O(n)์ด๊ณ , ๊ณต๊ฐ„๋ณต์žก๋„๋Š” O(n)์ž…๋‹ˆ๋‹ค. ๋” ์ตœ์ ์˜ ๊ณต๊ฐ„ ๋ณต์žก๋„๋ฅผ ์œ„ํ•ด O(1) ๊ณต๊ฐ„ ์†”๋ฃจ์…˜๋„ ๊ณ ๋ คํ•  ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค.

์ „๋ฐ˜์  ํ”ผ๋“œ๋ฐฑ

  • ๋ณต์žก๋„ ๋ช…์‹œ: ๊ฐ ํŒŒ์ผ ๋งจ ์œ„์— ๊ฐ„๋‹จํžˆ ์‹œ๊ฐ„/๊ณต๊ฐ„ ๋ณต์žก๋„๋ฅผ ์ฃผ์„์œผ๋กœ ์ ์–ด๋‘์‹œ๋ฉด ์ข‹๊ฒ ์Šต๋‹ˆ๋‹ค.
  • ๊ฐ€๋…์„ฑ: ๋ณ€์ˆ˜๋ช…๊ณผ ๊ตฌ์กฐ๋Š” ๋ช…ํ™•ํ•˜๋ฉฐ, ์ „์ฒด์ ์œผ๋กœ ์ž˜ ์ž‘์„ฑํ•˜์…จ์Šต๋‹ˆ๋‹ค.
  • ์ถ”๊ฐ€ ์ œ์•ˆ: ์ด๋ฏธ ์ข‹์€ ํ•ด๊ฒฐ์ฑ…๋“ค์ด๋‹ˆ, ๊ฐ€๋Šฅํ•˜๋‹ค๋ฉด ์‹œ๊ฐ„/๊ณต๊ฐ„ ๋ณต์žก๋„ ๋ถ„์„๊ณผ ํ•จ๊ป˜ ๋” ์ตœ์ ํ™”๋œ ๋ฐฉ๋ฒ•๋„ ๊ณ ๋ คํ•ด๋ณด์‹œ๋ฉด ํ•™์Šต์— ๋„์›€์ด ๋  ๊ฒƒ์ž…๋‹ˆ๋‹ค.

์ „์ฒด์ ์œผ๋กœ ๋งค์šฐ ํ›Œ๋ฅญํ•œ PR์ž…๋‹ˆ๋‹ค! ์•ž์œผ๋กœ๋„ ๋‹ค์–‘ํ•œ ์ ‘๊ทผ๋ฒ•์„ ์‹œ๋„ํ•˜๋ฉฐ ์ฝ”๋“œ ํ’ˆ์งˆ๊ณผ ํšจ์œจ์„ฑ์„ ๋ชจ๋‘ ๋†’์ด์‹œ๋Š” ๋ชจ์Šต ๊ธฐ๋Œ€ํ•˜๊ฒ ์Šต๋‹ˆ๋‹ค.

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14์ฃผ์ฐจ ๋ฌธ์ œ ํ’€์ด ๊ณ ์ƒํ•˜์…จ์Šต๋‹ˆ๋‹ค.
counting bits ๋ฌธ์ œ์˜ ๊ฒฝ์šฐ ๋‚ด์žฅ ํ•จ์ˆ˜๋ฅผ ์‚ฌ์šฉํ•ด๋„ ๊ดœ์ฐฎ์ง€๋งŒ, ๊ทผ๋ณธ์ ์ธ ํ’€์ด ๋ฐฉ๋ฒ•์„ ์ดํ•ดํ•˜๊ธฐ ์œ„ํ•ด bit operation์„ ์‚ฌ์šฉํ•˜์…”์„œ ํ’€์–ด๋ณด์‹œ๋ฉด ๋„์›€์ด ๋งŽ์ด ๋  ๊ฒƒ ๊ฐ™์•„์š”.
๊ธธ์—ˆ๋˜ 15์ฃผ๊ฐ„์˜ ์—ฌ์ •๋„ ๋‹ค์Œ์ฃผ๋ฉฐ ๋์ด๋„ค์š”. ๋งˆ์ง€๋ง‰๊นŒ์ง€ ํŒŒ์ดํŒ…์ž…๋‹ˆ๋‹ค!

@TonyKim9401 TonyKim9401 merged commit 3569df5 into DaleStudy:main Feb 14, 2026
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