๋ณธ๋ฌธ ๋ฐ”๋กœ๊ฐ€๊ธฐ
๋ฐ˜์‘ํ˜•

์ „์ฒด ๊ธ€396

[๋ฐฑ์ค€] 2217๋ฒˆ: ๋กœํ”„(๊ทธ๋ฆฌ๋””, ์ˆ˜ํ•™) https://www.acmicpc.net/problem/2217 2217๋ฒˆ: ๋กœํ”„ N(1≤N≤100,000)๊ฐœ์˜ ๋กœํ”„๊ฐ€ ์žˆ๋‹ค. ์ด ๋กœํ”„๋ฅผ ์ด์šฉํ•˜์—ฌ ์ด๋Ÿฐ ์ €๋Ÿฐ ๋ฌผ์ฒด๋ฅผ ๋“ค์–ด์˜ฌ๋ฆด ์ˆ˜ ์žˆ๋‹ค. ๊ฐ๊ฐ์˜ ๋กœํ”„๋Š” ๊ทธ ๊ตต๊ธฐ๋‚˜ ๊ธธ์ด๊ฐ€ ๋‹ค๋ฅด๊ธฐ ๋•Œ๋ฌธ์— ๋“ค ์ˆ˜ ์žˆ๋Š” ๋ฌผ์ฒด์˜ ์ค‘๋Ÿ‰์ด ์„œ๋กœ ๋‹ค๋ฅผ ์ˆ˜๋„ ์žˆ๋‹ค. ํ•˜์ง€๋งŒ ์—ฌ๋Ÿฌ ๊ฐœ์˜ ๋กœํ”„๋ฅผ ๋ณ‘๋ ฌ๋กœ ์—ฐ๊ฒฐํ•˜๋ฉด ๊ฐ๊ฐ์˜ ๋กœํ”„์— ๊ฑธ๋ฆฌ๋Š” ์ค‘๋Ÿ‰์„ ๋‚˜๋ˆŒ ์ˆ˜ ์žˆ๋‹ค. k๊ฐœ์˜ ๋กœํ”„๋ฅผ ์‚ฌ์šฉํ•˜์—ฌ ์ค‘๋Ÿ‰์ด w์ธ ๋ฌผ์ฒด๋ฅผ ๋“ค์–ด์˜ฌ๋ฆด ๋•Œ, ๊ฐ๊ฐ์˜ ๋กœํ”„์—๋Š” ๋ชจ๋‘ ๊ณ ๋ฅด๊ฒŒ w/k ๋งŒํผ์˜ ์ค‘๋Ÿ‰์ด ๊ฑธ๋ฆฌ๊ฒŒ ๋œ๋‹ค. ๊ฐ ๋กœํ”„๋“ค์— ๋Œ€ํ•œ ์ •๋ณด๊ฐ€ ์ฃผ์–ด์กŒ์„ ๋•Œ, ์ด ๋กœํ”„๋“ค์„ www.acmicpc.net ์ฝ”๋“œ import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.. 2020. 2. 19.
[Codeforces] 1154A - Restoring Three Numbers https://codeforces.com/problemset/problem/1154/A Problem - 1154A - Codeforces codeforces.com ๋ฌธ์ œ ํ•ด์„ Polycarp๋Š” a, b, c์˜ ์„ธ ๊ฐœ์˜ ์–‘์˜ ์ •์ˆ˜๋ฅผ ์ถ”์ธกํ–ˆ๋‹ค. ๊ทธ๋Š” ์ด ์ˆซ์ž๋“ค์„ ๋น„๋ฐ€์— ๋ถ€์น˜์ง€๋งŒ, ์ž„์˜์˜ ์ˆœ์„œ๋กœ ๊ฒŒ์‹œํŒ์— ๋„ค ๊ฐœ์˜ ์ˆซ์ž๋ฅผ ์ ๋Š”๋‹ค. ์ฆ‰, ๊ทธ๋“ค์˜ ์Œ์œผ๋กœ ๋œ ์ดํ•ฉ(3๊ฐœ์˜ ์ˆซ์ž)๊ณผ ์„ธ ๊ฐœ์˜ ์ˆซ์ž(1๊ฐœ์˜ ์ˆซ์ž)์˜ ํ•ฉ์ด๋‹ค. ๊ทธ๋ž˜์„œ ์ž„์˜์˜ ์ˆœ์„œ๋กœ ๊ธฐํŒ์—๋Š” a+b, a+c, b+c, a+b+c์˜ ๋„ค ๊ฐœ์˜ ์ˆซ์ž๊ฐ€ ์žˆ๋‹ค. ์ฃผ์–ด์ง„ ์ˆซ์ž๋ฅผ ์‚ฌ์šฉํ•ด์„œ a, b, c์˜ ์„ธ ์ˆซ์ž๋ฅผ ๋งžํ˜€์•ผ ํ•œ๋‹ค. ์–ด๋–ค ์ˆœ์„œ๋กœ๋“  ์„ธ ๊ฐœ์˜ ์ถ”์ธก๋œ ์ •์ˆ˜๋ฅผ ์ธ์‡„ํ•œ๋‹ค. ์ฃผ์–ด์ง„ ์ผ๋ถ€ ์ˆซ์ž a, b, c๊ฐ€ ๊ฐ™์„ ์ˆ˜ ์žˆ๋‹ค๋Š” ์ ์— ์œ ์˜ํ•œ๋‹ค(a=b=c๋„ ๊ฐ€๋Šฅํ•˜๋‹ค). ์ž…๋ ฅ .. 2020. 2. 19.
[๋ฐฑ์ค€] 15650๋ฒˆ: N๊ณผ M (2) (dfs, ๋ฐฑํŠธ๋ž˜ํ‚น) https://www.acmicpc.net/problem/15650 15650๋ฒˆ: N๊ณผ M (2) ํ•œ ์ค„์— ํ•˜๋‚˜์”ฉ ๋ฌธ์ œ์˜ ์กฐ๊ฑด์„ ๋งŒ์กฑํ•˜๋Š” ์ˆ˜์—ด์„ ์ถœ๋ ฅํ•œ๋‹ค. ์ค‘๋ณต๋˜๋Š” ์ˆ˜์—ด์„ ์—ฌ๋Ÿฌ ๋ฒˆ ์ถœ๋ ฅํ•˜๋ฉด ์•ˆ๋˜๋ฉฐ, ๊ฐ ์ˆ˜์—ด์€ ๊ณต๋ฐฑ์œผ๋กœ ๊ตฌ๋ถ„ํ•ด์„œ ์ถœ๋ ฅํ•ด์•ผ ํ•œ๋‹ค. ์ˆ˜์—ด์€ ์‚ฌ์ „ ์ˆœ์œผ๋กœ ์ฆ๊ฐ€ํ•˜๋Š” ์ˆœ์„œ๋กœ ์ถœ๋ ฅํ•ด์•ผ ํ•œ๋‹ค. www.acmicpc.net ์ฝ”๋“œ import java.util.Scanner; public class Main { public static int arr[]; public static boolean visit[]; public static int N; public static int M; public static StringBuilder sb = new StringBuilder(); public static vo.. 2020. 2. 18.
[๋ฐฑ์ค€] 15649๋ฒˆ: N๊ณผ M (1) (dfs, ๋ฐฑํŠธ๋ž˜ํ‚น) https://www.acmicpc.net/problem/15649 15649๋ฒˆ: N๊ณผ M (1) ํ•œ ์ค„์— ํ•˜๋‚˜์”ฉ ๋ฌธ์ œ์˜ ์กฐ๊ฑด์„ ๋งŒ์กฑํ•˜๋Š” ์ˆ˜์—ด์„ ์ถœ๋ ฅํ•œ๋‹ค. ์ค‘๋ณต๋˜๋Š” ์ˆ˜์—ด์„ ์—ฌ๋Ÿฌ ๋ฒˆ ์ถœ๋ ฅํ•˜๋ฉด ์•ˆ๋˜๋ฉฐ, ๊ฐ ์ˆ˜์—ด์€ ๊ณต๋ฐฑ์œผ๋กœ ๊ตฌ๋ถ„ํ•ด์„œ ์ถœ๋ ฅํ•ด์•ผ ํ•œ๋‹ค. ์ˆ˜์—ด์€ ์‚ฌ์ „ ์ˆœ์œผ๋กœ ์ฆ๊ฐ€ํ•˜๋Š” ์ˆœ์„œ๋กœ ์ถœ๋ ฅํ•ด์•ผ ํ•œ๋‹ค. www.acmicpc.net ์ฝ”๋“œ import java.util.Scanner; public class Main { static int arr[]; static boolean visit[]; static int N; static int M; static StringBuilder sb = new StringBuilder(); public static void dfs(int count) { // dfs ํ•จ์ˆ˜ ํƒˆ์ถœ - .. 2020. 2. 18.
[๋ฐฑ์ค€] 6986๋ฒˆ: ์ ˆ์‚ฌํ‰๊ท  https://www.acmicpc.net/problem/6986 6986๋ฒˆ: ์ ˆ์‚ฌํ‰๊ท  ์ฒซ์งธ ์ค„์— ์ ˆ์‚ฌํ‰๊ท (N, K)๋ฅผ, ๋‘˜์งธ ์ค„์— ๋ณด์ •ํ‰๊ท (N, K)๋ฅผ ๊ฐ๊ฐ ์†Œ์ˆ˜์ ์ดํ•˜ ์…‹์งธ ์ž๋ฆฌ์—์„œ ๋ฐ˜์˜ฌ๋ฆผํ•˜์—ฌ ๋‘˜์งธ ์ž๋ฆฌ๊นŒ์ง€ ์ถœ๋ ฅํ•œ๋‹ค. ์˜ˆ๋ฅผ ๋“ค์–ด ๊ฒฐ๊ณผ๊ฐ’์ด 9.667์ธ ๊ฒฝ์šฐ 9.67๋กœ, 5์ธ ๊ฒฝ์šฐ 5.00์œผ๋กœ, 5.5์ธ ๊ฒฝ์šฐ์—๋Š” 5.50์œผ๋กœ ์ถœ๋ ฅํ•œ๋‹ค. www.acmicpc.net ์ฝ”๋“œ import java.util.Arrays; import java.util.Scanner; public class Main { public static double []dArr; public static int N; public static int K; // ์ ˆ์‚ฌ ํ‰๊ท  public static String julsa(int num) { do.. 2020. 2. 14.
[Codeforces] 791A: Bear and Big Brother https://codeforces.com/problemset/problem/791/A Problem - 791A - Codeforces codeforces.com ๋ฒ ์–ด ๋ฆฌ๋งฅ์€ ๊ณฐ ์ค‘์—์„œ ๊ฐ€์žฅ ํฐ ๊ฒƒ์ด ๋˜๊ฑฐ๋‚˜, ์ ์–ด๋„ ๊ทธ์˜ ๋™์ƒ ๋ฐฅ๋ณด๋‹ค ๋” ์ปค์ง€๊ธฐ๋ฅผ ์›ํ•œ๋‹ค. ํ˜„์žฌ ๋ฆฌ๋งฅ๊ณผ ๋ฐฅ์˜ ๋ชธ๋ฌด๊ฒŒ๋Š” ๊ฐ๊ฐ a์™€ b์ด๋‹ค. ๋ฆฌ๋งฅ์˜ ๋ชธ๋ฌด๊ฒŒ๊ฐ€ ๋™์ƒ์˜ ๋ชธ๋ฌด๊ฒŒ๋ณด๋‹ค ์ž‘๊ฑฐ๋‚˜ ๊ฐ™์Œ์„ ๋ณด์ฆํ•œ๋‹ค. ๋ฆฌ๋งฅ์€ ๋งŽ์ด ๋จน๊ณ  ๋ชธ๋ฌด๊ฒŒ๋Š” ํ•ด๋งˆ๋‹ค ์„ธ ๋ฐฐ๊ฐ€ ๋˜๋Š” ๋ฐ˜๋ฉด ๋ฐฅ์˜ ๋ชธ๋ฌด๊ฒŒ๋Š” ํ•ด๋งˆ๋‹ค ๋‘ ๋ฐฐ๊ฐ€ ๋œ๋‹ค. ๋ฆฌ๋งฅ์€ ๋ช‡ ๋…„์„ ๊ผฌ๋ฐ• ์ง€๋‚ธ ํ›„์— ๋ฐฅ๋ณด๋‹ค ์—„๊ฒฉํ•˜๊ฒŒ ๋” ์ปค์ง€๊ฒŒ ๋  ๊ฒƒ์ธ๊ฐ€? ์ž…๋ ฅ ์ž…๋ ฅ์˜ ์œ ์ผํ•œ ์„ ์€ ๊ฐ๊ฐ ๋ฆฌ๋งฅ์˜ ๋ฌด๊ฒŒ์™€ ๋ฐฅ์˜ ๋ฌด๊ฒŒ์ธ ๋‘ ๊ฐœ์˜ ์ •์ˆ˜ a์™€ b๋ฅผ ํฌํ•จํ•œ๋‹ค. ์‚ฐ์ถœ๋Ÿ‰ 1๊ฐœ์˜ ์ •์ˆ˜๋ฅผ ์ธ์‡„ํ•˜๊ณ , ๊ทธ ์ดํ›„์˜ ์ •์ˆ˜๋ฅผ ๋‚˜ํƒ€๋‚ด๋ฉฐ, ๋ฆฌ๋งฅ์€ ๋ฐฅ๋ณด๋‹ค ์—„๊ฒฉํžˆ ์ปค์ง„๋‹ค. ๋ฉ”๋ชจ.. 2020. 2. 13.
[๋ฐฑ์ค€] 1931๋ฒˆ: ํšŒ์˜์‹ค๋ฐฐ์ •(๊ทธ๋ฆฌ๋””, ์ •๋ ฌ) https://www.acmicpc.net/problem/1931 1931๋ฒˆ: ํšŒ์˜์‹ค๋ฐฐ์ • (1,4), (5,7), (8,11), (12,14) ๋ฅผ ์ด์šฉํ•  ์ˆ˜ ์žˆ๋‹ค. www.acmicpc.net ์ฝ”๋“œ import java.util.Arrays; import java.util.Comparator; import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner scan = new Scanner(System.in); int N = scan.nextInt(); int[][] arr = new int[N][2];// ํšŒ์˜ ๋ณ„ ์‹œ์ž‘, ์ข…๋ฃŒ ์‹œ๊ฐ„ ์ €์žฅํ•  ๋ฐฐ์—ด for(int i=0; i ์ข…๋ฃŒ ์‹œ๊ฐ„์ด ๊ฐ™์„ ๊ฒฝ์šฐ ์‹œ์ž‘.. 2020. 2. 12.
[๋ฐฑ์ค€] 2468๋ฒˆ: ์•ˆ์ „ ์˜์—ญ(์™„์ „ํƒ์ƒ‰, ๊ทธ๋ž˜ํ”„) https://www.acmicpc.net/problem/2468 2468๋ฒˆ: ์•ˆ์ „ ์˜์—ญ ์žฌ๋‚œ๋ฐฉ์žฌ์ฒญ์—์„œ๋Š” ๋งŽ์€ ๋น„๊ฐ€ ๋‚ด๋ฆฌ๋Š” ์žฅ๋งˆ์ฒ ์— ๋Œ€๋น„ํ•ด์„œ ๋‹ค์Œ๊ณผ ๊ฐ™์€ ์ผ์„ ๊ณ„ํšํ•˜๊ณ  ์žˆ๋‹ค. ๋จผ์ € ์–ด๋–ค ์ง€์—ญ์˜ ๋†’์ด ์ •๋ณด๋ฅผ ํŒŒ์•…ํ•œ๋‹ค. ๊ทธ ๋‹ค์Œ์— ๊ทธ ์ง€์—ญ์— ๋งŽ์€ ๋น„๊ฐ€ ๋‚ด๋ ธ์„ ๋•Œ ๋ฌผ์— ์ž ๊ธฐ์ง€ ์•Š๋Š” ์•ˆ์ „ํ•œ ์˜์—ญ์ด ์ตœ๋Œ€๋กœ ๋ช‡ ๊ฐœ๊ฐ€ ๋งŒ๋“ค์–ด ์ง€๋Š” ์ง€๋ฅผ ์กฐ์‚ฌํ•˜๋ ค๊ณ  ํ•œ๋‹ค. ์ด๋•Œ, ๋ฌธ์ œ๋ฅผ ๊ฐ„๋‹จํ•˜๊ฒŒ ํ•˜๊ธฐ ์œ„ํ•˜์—ฌ, ์žฅ๋งˆ์ฒ ์— ๋‚ด๋ฆฌ๋Š” ๋น„์˜ ์–‘์— ๋”ฐ๋ผ ์ผ์ •ํ•œ ๋†’์ด ์ดํ•˜์˜ ๋ชจ๋“  ์ง€์ ์€ ๋ฌผ์— ์ž ๊ธด๋‹ค๊ณ  ๊ฐ€์ •ํ•œ๋‹ค. ์–ด๋–ค ์ง€์—ญ์˜ ๋†’์ด ์ •๋ณด๋Š” ํ–‰๊ณผ ์—ด์˜ ํฌ๊ธฐ๊ฐ€ ๊ฐ๊ฐ N์ธ 2์ฐจ์› ๋ฐฐ์—ด ํ˜•ํƒœ๋กœ ์ฃผ์–ด www.acmicpc.net ์ฝ”๋“œ import java.util.Scanner; public class Main { static int map[][];// 2์ฐจ์› .. 2020. 2. 12.
[Codeforces] 1030A: In Search of an Easy Problem https://codeforces.com/problemset/problem/1030/A Problem - 1030A - Codeforces codeforces.com ์ฝ”๋ฐํฌ๋ ˆ์ด์…˜ ์ฝ”๋””๋„ค์ดํ„ฐ๋“ค์€ ํ† ๋„ˆ๋จผํŠธ๋ฅผ ์ค€๋น„ํ•  ๋•Œ ์ฒซ ๋ฒˆ์งธ ๋ฌธ์ œ๋ฅผ ์ตœ๋Œ€ํ•œ ์‰ฝ๊ฒŒ ๋งŒ๋“ค๊ธฐ ์œ„ํ•ด ์ตœ์„ ์„ ๋‹คํ•œ๋‹ค. ์ด๋ฒˆ์—๋Š” ์ฝ”๋””๋„ค์ดํ„ฐ๊ฐ€ ๋ช‡ ๊ฐ€์ง€ ๋ฌธ์ œ์ ์„ ๊ณจ๋ผ์„œ n๋ช…์˜ ์‚ฌ๋žŒ๋“ค์—๊ฒŒ ๊ทธ๋“ค์˜ ์˜๊ฒฌ์— ๋Œ€ํ•ด ๋ฌผ์—ˆ๋‹ค. ์ด ๋ฌธ์ œ๊ฐ€ ์‰ฌ์šด ๊ฒƒ์ธ์ง€ ์–ด๋ ค์šด ๊ฒƒ์ธ์ง€ ๊ฐ์ž๊ฐ€ ๋Œ€๋‹ตํ–ˆ๋‹ค. ์ด n๋ช… ์ค‘ ์ ์–ด๋„ ํ•œ ๋ช…์ด ๋ฌธ์ œ๊ฐ€ ์–ด๋ ต๋‹ค๊ณ  ๋Œ€๋‹ตํ–ˆ๋‹ค๋ฉด ์กฐ์ •์ž๋Š” ๋ฌธ์ œ๋ฅผ ๋ฐ”๊พธ๊ธฐ๋กœ ๊ฒฐ์ •ํ•œ๋‹ค. ์ฃผ์–ด์ง„ ์‘๋‹ต์— ๋Œ€ํ•ด์„œ๋Š” ๋ฌธ์ œ๊ฐ€ ์ถฉ๋ถ„ํžˆ ์‰ฌ์šด์ง€ ํ™•์ธํ•˜์‹ญ์‹œ์˜ค. ์ž…๋ ฅ ์ฒซ ๋ฒˆ์งธ ์ค„์—๋Š” ๋‹จ์ผ ์ •์ˆ˜ n(1 ≤100) - ์ž์‹ ์˜ ์˜๊ฒฌ์„ ์ œ์‹œํ•˜๋ผ๋Š” ์‚ฌ๋žŒ์˜ ์ˆ˜๊ฐ€ ํฌํ•จ๋˜์–ด ์žˆ๋‹ค. ๋‘ ๋ฒˆ์งธ ์ค„์€ n๊ฐœ์˜ ์ •์ˆ˜๋ฅผ ํฌํ•จํ•˜.. 2020. 2. 12.
[Codeforces] 977A: Wrong Subtraction https://codeforces.com/problemset/problem/977/A Problem - 977A - Codeforces codeforces.com ์–ด๋ฆฐ ์†Œ๋…€ ํƒ€๋ƒ๋Š” ์ˆซ์ž๋ฅผ ํ•˜๋‚˜ ์ค„์ด๋Š” ๋ฒ•์„ ๋ฐฐ์šฐ๊ณ  ์žˆ์ง€๋งŒ, ๋‘ ์ž๋ฆฌ ํ˜น์€ ๊ทธ ์ด์ƒ์˜ ์ˆซ์ž๋กœ ๊ตฌ์„ฑ๋œ ์ˆซ์ž๋กœ ์ž˜๋ชปํ•œ๋‹ค. ํƒ€๋ƒ๋Š” ๋‹ค์Œ ์•Œ๊ณ ๋ฆฌ์ฆ˜์œผ๋กœ ์ˆซ์ž์—์„œ ํ•˜๋‚˜๋ฅผ ๋บ€๋‹ค. ์ˆซ์ž์˜ ๋งˆ์ง€๋ง‰ ์ˆซ์ž๊ฐ€ 0์ด ์•„๋‹Œ ๊ฒฝ์šฐ, ๊ทธ๋…€๋Š” ์ˆซ์ž๋ฅผ 1๋กœ ์ค„์ธ๋‹ค. ์ˆซ์ž์˜ ๋งˆ์ง€๋ง‰ ์ˆซ์ž๊ฐ€ 0์ด๋ฉด, ๊ทธ๋…€๋Š” ์ˆซ์ž๋ฅผ 10์œผ๋กœ ๋‚˜๋ˆˆ๋‹ค. ์ •์ˆ˜ n์ด ์ฃผ์–ด์ง„๋‹ค. ํƒ€๋ƒ๋Š” ๊ทธ๊ฒƒ์—์„œ ํ•˜๋‚˜๋ฅผ ๋บ„ ๊ฒƒ์ด๋‹ค. ๋‹น์‹ ์˜ ์ž„๋ฌด๋Š” ๋ชจ๋“  k์˜ ์†Œ์‚ฐ ํ›„์— ๊ฒฐ๊ณผ๋ฅผ ์ธ์‡„ํ•˜๋Š” ๊ฒƒ์ด๋‹ค. ๊ฒฐ๊ณผ๋Š” ์–‘์˜ ์ •์ˆ˜์ผ ๊ฒƒ์„ ๋ณด์žฅํ•œ๋‹ค. ์ž…๋ ฅ ์ž…๋ ฅ์˜ ์ฒซ ๋ฒˆ์งธ ๋ผ์ธ์€ 2๊ฐœ์˜ ์ •์ˆ˜ n๊ณผ k (109, 1 ≤kl50) - ํƒ€๋ƒ๊ฐ€ ๋นผ๋Š” ์ˆ˜์™€ ๊ทธ.. 2020. 2. 11.
๋ฐ˜์‘ํ˜•