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spring0913spring0913
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Merge branch 'week7'
2 parents 9954f50 + 5e97feb commit 3d41d7f

7 files changed

+362
-0
lines changed

‎week7/BOJ_11404(플로이드).java

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import java.io.*;
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import java.util.*;
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public class Main {
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public static final int MAX = 10_000_001;
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public static void main(String[] args) throws IOException {
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BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
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int n = Integer.parseInt(br.readLine());
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int m = Integer.parseInt(br.readLine());
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int[][] graph = new int[n+1][n+1];
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for(int i=1; i<=n; i++) {
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for(int j=1; j<=n; j++) {
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if(i == j) {
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graph[i][j] = 0;
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}else {
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graph[i][j] = MAX;
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}
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}
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}
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for(int i=0; i<m; i++) {
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StringTokenizer st = new StringTokenizer(br.readLine());
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int a = Integer.parseInt(st.nextToken());
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int b = Integer.parseInt(st.nextToken());
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int c = Integer.parseInt(st.nextToken());
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graph[a][b] = Math.min(graph[a][b], c);
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}
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for(int k=1; k<=n; k++) {
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for(int i=1; i<=n; i++) {
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for(int j=1; j<=n; j++) {
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graph[i][j] = Math.min(graph[i][j], graph[i][k] + graph[k][j]);
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}
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}
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}
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StringBuffer sb = new StringBuffer();
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for(int i=1; i<=n; i++) {
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for(int j=1; j<=n; j++) {
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sb.append((graph[i][j] == MAX) ? 0 : graph[i][j]).append(' ');
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}
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sb.append('\n');
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}
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System.out.print(sb);
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}
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}

‎week7/BOJ_11657(타임머신).java

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import java.io.*;
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import java.util.*;
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public class Main {
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public static int city;
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public static List<List<int[]>> graph;
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public static long[] dist;
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public static void main(String[] args) throws IOException {
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BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
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StringTokenizer st = new StringTokenizer(br.readLine());
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city = Integer.parseInt(st.nextToken());
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int bus = Integer.parseInt(st.nextToken());
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graph = new ArrayList<>();
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dist = new long[city+1];
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for(int i=0; i<=city; i++) {
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graph.add(new ArrayList<>());
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dist[i] = Long.MAX_VALUE;
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}
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for(int i=0; i<bus; i++) {
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st = new StringTokenizer(br.readLine());
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int v1 = Integer.parseInt(st.nextToken());
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int v2 = Integer.parseInt(st.nextToken());
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int cost = Integer.parseInt(st.nextToken());
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graph.get(v1).add(new int[]{v2, cost});
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}
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bellmanFord(1);
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}
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public static void bellmanFord(int start) {
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dist[start] = 0;
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for(int i=1; i<=city; i++) {
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for(int j=1; j<=city; j++) {
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List<int[]> list = graph.get(j);
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for(int k=0; k<list.size(); k++) {
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int nextV = list.get(k)[0];
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int nextCost = list.get(k)[1];
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if(dist[j] != Long.MAX_VALUE && dist[nextV] > dist[j] + nextCost) {
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dist[nextV] = dist[j] + nextCost;
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// city(정점 개수)번째 반복에 갱신되는 값이 있으면 음수 사이클 존재
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if(i == city) {
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System.out.println("-1");
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return;
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}
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}
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}
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}
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}
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for(int i=2; i<=city; i++) {
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System.out.println((dist[i] == Long.MAX_VALUE) ? "-1" : dist[i]);
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}
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}
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}

‎week7/BOJ_1389(케빈 베이컨의 6단계 법칙).java

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import java.io.*;
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import java.util.*;
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public class Main {
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public static void main(String[] args) throws IOException {
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BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
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StringTokenizer st = new StringTokenizer(br.readLine());
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int N = Integer.parseInt(st.nextToken());
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int M = Integer.parseInt(st.nextToken());
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int[][] graph = new int[N+1][N+1];
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for(int i=1; i<=N; i++) {
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for(int j=1; j<=N; j++) {
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if(i == j) {
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graph[i][j] = 0;
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}else {
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graph[i][j] = 1000;
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}
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}
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}
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for(int i=0; i<M; i++) {
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st = new StringTokenizer(br.readLine());
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int A = Integer.parseInt(st.nextToken());
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int B = Integer.parseInt(st.nextToken());
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graph[A][B] = graph[B][A] = 1;
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}
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for(int k=1; k<=N; k++) {
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for(int i=1; i<=N; i++) {
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for(int j=1; j<=N; j++) {
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graph[i][j] = Math.min(graph[i][j], graph[i][k] + graph[k][j]);
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}
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}
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}
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int[] count = new int[N+1];
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for(int i=1; i<=N; i++) {
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for(int j=1; j<=N; j++) {
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count[i] += graph[i][j];
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}
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}
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int answer = 1;
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for(int i=1; i<=N; i++) {
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if(count[answer] > count[i]) {
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answer = i;
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}
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}
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System.out.println(answer);
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}
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}

‎week7/BOJ_15723(n단 논법).java

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import java.io.*;
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import java.util.*;
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public class Main {
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public static int n;
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public static boolean[][] graph;
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public static void main(String[] args) throws IOException {
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BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
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n = Integer.parseInt(br.readLine());
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graph = new boolean[27][27];
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for(int i=0; i<n; i++) {
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StringTokenizer st = new StringTokenizer(br.readLine());
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int a = st.nextToken().charAt(0) - 'a';
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st.nextToken();
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int b = st.nextToken().charAt(0) - 'a';
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graph[a][b] = true;
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}
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int m = Integer.parseInt(br.readLine());
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StringBuffer sb = new StringBuffer();
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for(int i=0; i<m; i++) {
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StringTokenizer st = new StringTokenizer(br.readLine());
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int a = st.nextToken().charAt(0) - 'a';
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st.nextToken();
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int b = st.nextToken().charAt(0) - 'a';
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sb.append(bfs(a, b)).append('\n');
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}
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System.out.print(sb);
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}
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public static char bfs(int start, int end) {
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boolean[] visited = new boolean[27];
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Queue<Integer> q = new LinkedList<>();
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q.offer(start);
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while(!q.isEmpty()) {
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int v = q.poll();
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if(v == end) {
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return 'T';
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}
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for(int i=0; i<27; i++) {
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if(graph[v][i] && !visited[i]) {
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visited[i] = true;
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q.offer(i);
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}
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}
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}
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return 'F';
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}
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}

‎week7/BOJ_18243(Small World Network).java

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import java.io.*;
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import java.util.*;
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public class Main {
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public static void main(String[] args) throws IOException {
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BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
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StringTokenizer st = new StringTokenizer(br.readLine());
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int N = Integer.parseInt(st.nextToken());
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int M = Integer.parseInt(st.nextToken());
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int[][] graph = new int[N+1][N+1];
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for(int i=1; i<=N; i++) {
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for(int j=1; j<=N; j++) {
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if(i == j) {
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graph[i][j] = 0;
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}else {
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graph[i][j] = 100;
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}
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}
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}
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for(int i=0; i<M; i++) {
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st = new StringTokenizer(br.readLine());
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int A = Integer.parseInt(st.nextToken());
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int B = Integer.parseInt(st.nextToken());
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graph[A][B] = graph[B][A] = 1;
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}
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for(int k=1; k<=N; k++) {
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for(int i=1; i<=N; i++) {
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for(int j=1; j<=N; j++) {
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graph[i][j] = Math.min(graph[i][j], graph[i][k] + graph[k][j]);
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}
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}
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}
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for(int i=1; i<=N; i++) {
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for(int j=1; j<=N; j++) {
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if(graph[i][j] > 6) {
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System.out.println("Big World!");
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return;
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}
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}
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}
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System.out.println("Small World!");
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}
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}

‎week7/BOJ_1916(최소비용 구하기).java

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import java.io.*;
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import java.util.*;
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public class Main {
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public static int city;
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public static List<List<int[]>> graph;
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public static int[] dist;
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public static void main(String[] args) throws IOException {
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BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
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city = Integer.parseInt(br.readLine());
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int bus = Integer.parseInt(br.readLine());
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graph = new ArrayList<>();
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dist = new int[city+1];
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for(int i=0; i<=city; i++) {
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graph.add(new ArrayList<>());
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dist[i] = Integer.MAX_VALUE;
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}
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for(int i=0; i<bus; i++) {
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StringTokenizer st = new StringTokenizer(br.readLine());
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int v1 = Integer.parseInt(st.nextToken());
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int v2 = Integer.parseInt(st.nextToken());
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int cost = Integer.parseInt(st.nextToken());
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graph.get(v1).add(new int[]{v2, cost});
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}
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StringTokenizer st = new StringTokenizer(br.readLine());
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int start = Integer.parseInt(st.nextToken());
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int end = Integer.parseInt(st.nextToken());
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dijkstra(start, end);
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}
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public static void dijkstra(int start, int end) {
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PriorityQueue<int[]> pq = new PriorityQueue<>((o1, o2) -> Integer.compare(o1[1], o2[1]));
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pq.offer(new int[]{start, 0});
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while(!pq.isEmpty()) {
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int v = pq.peek()[0];
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int cost = pq.peek()[1];
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pq.poll();
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if(dist[v] < cost) {
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continue;
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}
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List<int[]> list = graph.get(v);
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for(int i=0; i<list.size(); i++) {
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int nextV = list.get(i)[0];
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int nextCost = list.get(i)[1];
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if(dist[nextV] > cost + nextCost) {
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dist[nextV] = cost + nextCost;
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pq.offer(new int[]{nextV, dist[nextV]});
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}
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}
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}
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System.out.println(dist[end]);
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}
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}

‎week7/BOJ_5972(택배 배송).java

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import java.io.*;
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import java.util.*;
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public class Main {
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public static List<List<int[]>> graph;
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public static int[] dist;
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public static int N;
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public static void main(String[] args) throws IOException {
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BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
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StringTokenizer st = new StringTokenizer(br.readLine());
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N = Integer.parseInt(st.nextToken());
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int M = Integer.parseInt(st.nextToken());
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graph = new ArrayList<>();
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dist = new int[N+1];
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for(int i=0; i<=N; i++) {
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graph.add(new ArrayList<>());
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dist[i] = Integer.MAX_VALUE;
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}
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for(int i=0; i<M; i++) {
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st = new StringTokenizer(br.readLine());
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int A = Integer.parseInt(st.nextToken());
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int B = Integer.parseInt(st.nextToken());
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int C = Integer.parseInt(st.nextToken());
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graph.get(A).add(new int[]{B, C});
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graph.get(B).add(new int[]{A, C});
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}
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dijkstra();
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}
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public static void dijkstra(){
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PriorityQueue<int[]> pq = new PriorityQueue<>((o1, o2) -> Integer.compare(o1[1], o2[1]));
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pq.offer(new int[]{1, 0});
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while(!pq.isEmpty()) {
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int v = pq.peek()[0];
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int cost = pq.peek()[1];
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pq.poll();
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// 중복 방문 방지
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if(dist[v] < cost) {
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continue;
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}
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List<int[]> list = graph.get(v);
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for(int i=0; i<list.size(); i++) {
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int nextV = list.get(i)[0];
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int nextCost = list.get(i)[1];
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if(dist[nextV] > cost + nextCost) {
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dist[nextV] = cost + nextCost;
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pq.offer(new int[]{nextV, dist[nextV]});
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}
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}
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}
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System.out.println(dist[N]);
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}
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}

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