2조 장다은 / 11월 1주차 / 목

daeun/boj1043.java

@@ -0,0 +1,91 @@
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.Queue;
+import java.util.Scanner;
+
+public class Main {
+
+	static boolean visited[];
+
+	public static void main(String[] args) {
+		Scanner sc=  new Scanner(System.in);
+		int N= sc.nextInt(); //총 사람 수 (1부터)(노드 번호)
+		int M = sc.nextInt();//파티 수(간선 수)
+		int K = sc.nextInt();//진실아는 사람 수
+
+		visited = new boolean[N+1];
+		ArrayList<Integer>[] graph = new ArrayList[N+1];
+
+		for(int i=1; i<=N; i++) {
+			graph[i] = new ArrayList<>();
+		}
+
+		boolean[] knowT = new boolean[N+1];
+		for(int i=0; i<K; i++) {
+			int knowp = sc.nextInt();//아는 사람 번호
+			knowT[knowp] = true;
+		}
+
+
+		ArrayList<Integer>[] parties = new ArrayList[M];
+		for(int i=0; i<M; i++) {
+			int partynum = sc.nextInt();//각 파티마다 오는 사람 수
+			parties[i] = new ArrayList<>();
+			for(int j=0; j<partynum; j++) {
+				int p = sc.nextInt();
+				parties[i].add(p); //각 파티에 오는사람들 추가
+
+			}
+
+			for(int j =0; j<parties[i].size(); j++) {
+				for(int k=j+1; k<parties[i].size(); k++) {
+					graph[parties[i].get(j)].add(parties[i].get(k));
+					graph[parties[i].get(k)].add(parties[i].get(j));
+				}
+			}
+		}
+
+		for(int i=1; i<=N; i++) {
+			if(knowT[i] && !visited[i]) {
+				bfs(graph, i);
+
+			}
+		}
+
+		int cnt =0;
+		for(int i=0; i<M; i++) {
+			boolean dontknow = true;
+			for(int p :parties[i]) {
+				if(visited[p])
+					dontknow = false;
+					break;
+			}
+			if(dontknow) {
+
+				cnt++;
+			}
+		}
+
+		System.out.println(cnt);
+
+
+	}//main
+
+	static void bfs(ArrayList<Integer>[] graph, int num) {
+		Queue<Integer>q = new LinkedList<>();
+		q.add(num);
+		visited[num] = true;
+
+		while(!q.isEmpty()) {
+			int curr =q.poll();//현재 사람
+			for(int next: graph[curr]) { 
+				if(!visited[next]) {
+					visited[next] = true;
+					q.add(next);
+				}
+			}
+		}
+
+	}
+
+}

daeun/boj1068.java

@@ -0,0 +1,4 @@
+
+public class boj1068 {
+
+}

daeun/boj1197.java

@@ -0,0 +1,105 @@
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.PriorityQueue;
+import java.util.StringTokenizer;
+
+public class 최소스패닝트리 {
+
+	static int V, E;
+
+
+	static class Edge implements Comparable<Edge> {
+
+		int to; //방문 정점
+		int cost; //가중치
+
+		public Edge(int to, int cost) {
+			this.to =to;
+			this.cost = cost;
+		}
+
+		@Override
+		public int compareTo(Edge o) {
+			return Integer.compare(this.cost, o.cost);
+		}
+
+
+	}
+
+	public static void main(String[] args) throws IOException {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		StringTokenizer st;
+		st = new StringTokenizer(br.readLine());
+		V = Integer.parseInt(st.nextToken());
+		E = Integer.parseInt(st.nextToken());
+
+		List<Edge>[] graph= new ArrayList[V+1]; //간선들을 리스트로 저장하니까
+
+		for(int i=1; i<=V; i++) {
+			graph[i] = new ArrayList<>();
+		}
+
+		for(int i=0; i<E; i++)  {
+			st = new StringTokenizer(br.readLine());
+
+			int a = Integer.parseInt(st.nextToken());
+			int b = Integer.parseInt(st.nextToken());
+			int cost = Integer.parseInt(st.nextToken());
+
+
+			graph[a].add(new Edge(b, cost));
+			graph[b].add(new Edge(a, cost));
+
+
+		}
+		int total = prim(graph);
+
+
+		System.out.println(total);
+	}//main
+
+
+	private static int prim(List<Edge>[] graph) {
+		int total =0;
+		PriorityQueue<Edge>  pq = new PriorityQueue<>();
+		boolean visited[] = new boolean [V+1];
+
+		pq.add(new Edge(1, 0));
+
+		while(!pq.isEmpty()) {
+			Edge edge = pq.poll();
+
+			int currNode = edge.to;
+			int cost = edge.cost;
+
+			if(visited[currNode]) {
+				continue;
+			}
+
+
+			total+= cost;
+			visited[currNode] = true;
+
+
+			for(Edge e: graph[currNode]) {
+				if(!visited[e.to]) {
+					pq.add(e);
+				}
+			}
+
+		}
+
+		return total;
+
+	}
+
+
+
+
+
+}

daeun/boj1647.java

@@ -0,0 +1,102 @@
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.PriorityQueue;
+import java.util.StringTokenizer;
+
+public class 도시분할계획 {
+
+	static int N, M; //마을(정점), 길(간선)
+
+
+	static class Edge implements Comparable<Edge> {
+
+		int to;
+		int cost;
+		public Edge(int to, int cost) {
+			this.to = to;
+			this.cost = cost;
+		}
+
+		@Override
+		public int compareTo(Edge o) {
+			return this.cost - o.cost; //가중치 기준 오름차순 정렬할 것 
+		}
+
+	}
+
+
+	public static void main(String[] args) throws IOException {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+
+		StringTokenizer st;
+		st = new StringTokenizer(br.readLine());
+
+		N = Integer.parseInt(st.nextToken());
+		M = Integer.parseInt(st.nextToken());
+
+		List<Edge> graph[] = new ArrayList[N+1];
+
+		for(int i=1; i<=N; i++) {
+			graph[i] = new ArrayList<>();
+		}
+
+
+		for(int i=0; i<M; i++) {
+			st = new StringTokenizer(br.readLine());
+			int A = Integer.parseInt(st.nextToken());
+			int B = Integer.parseInt(st.nextToken());
+			int C = Integer.parseInt(st.nextToken());
+
+			graph[A].add(new Edge(B, C));
+			graph[B].add(new Edge(A, C));
+
+		}
+
+
+		int total = prim(graph);
+
+		System.out.println(total);
+
+
+	}//main
+
+
+	//프림
+	private static int prim(List<Edge>[] graph) {
+		boolean visited[] = new boolean[N+1];
+		PriorityQueue<Edge> pq = new PriorityQueue<>();
+		int total =0;
+		int maxcost =0;
+		pq.add(new Edge(1,0));
+
+
+		while(!pq.isEmpty()) {
+			Edge edge = pq.poll();
+			int currNode = edge.to;
+			int cost = edge.cost;
+
+			if(visited[currNode]) {
+				continue;
+			}
+
+			visited[currNode] = true;
+			total+=cost;
+
+			maxcost = Math.max(maxcost, cost);
+
+			for(Edge e: graph[currNode]) {
+				if(!visited[e.to]) {
+					pq.add(new Edge(e.to, e.cost));
+				}
+			}
+
+
+		}
+
+		return total-maxcost;
+	}	
+
+}

daeun/boj1707.java

@@ -0,0 +1,76 @@
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.Queue;
+import java.util.Scanner;
+
+public class 이분그래프 {
+
+	static int visited[];
+	static int V, E;
+	static boolean isgraph;
+
+
+	public static void main(String[] args) {
+		Scanner sc = new Scanner(System.in);
+		int K = sc.nextInt();
+
+
+
+		for(int i=0; i<K; i++) {
+			isgraph = true;
+			 V = sc.nextInt();//정점 개수(1부터 시작)
+			 E = sc.nextInt();//간선ㄱ ㅐ수
+			 visited =  new int[V+1];
+			 ArrayList<Integer>[] graph = new ArrayList[V+1];
+			for(int j=1; j<=V; j++) {
+				graph[j] = new ArrayList<>();
+			}
+
+			for(int j=0; j<E; j++) {
+				int num1 = sc.nextInt();
+				int num2 = sc.nextInt();
+				graph[num1].add(num2);
+				graph[num2].add(num1);
+			}
+
+			for(int k=1; k<=V; k++) {
+				if(visited[k]==0) {
+					if(!bfs(graph, k)) {
+						isgraph= false;
+						break;
+					}
+				}
+
+			}
+
+			if(isgraph)
+				System.out.println("YES");
+			else 
+				System.out.println("NO");
+
+		}//k줄
+	}//main
+
+
+	static boolean bfs(ArrayList<Integer>[] graph, int num) {
+		Queue<Integer> q = new LinkedList<>();
+		q.add(num);
+		visited[num]=1;
+		while(!q.isEmpty()) {
+			int curr = q.poll();
+
+			for(int next: graph[curr]) {
+				if(visited[next]==0) {
+					visited[next] =(visited[curr]==1)? 2:1; 
+					q.add(next);
+				}else if(visited[next]==visited[curr]) {
+					return false;
+				}
+			}
+		}
+
+		return true;
+
+	}
+
+}