이상억 37주차

week37/이상억/backjoon/DFS와BFS.java

@@ -0,0 +1,76 @@
+import java.util.*;
+import java.io.*;
+
+
+public class Main{
+
+    static int N,M,V;
+    static List<Integer>[] graph;
+
+    static boolean[] visited;
+
+    public static void main(String[] args) throws IOException{
+
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+        V = Integer.parseInt(st.nextToken());
+
+        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());
+
+            graph[a].add(b);
+            graph[b].add(a);
+        }
+
+        for(int i = 1; i <= N; i++){
+            Collections.sort(graph[i]);
+        }
+
+        visited = new boolean[N+1];
+        dfs(V);
+        System.out.println();
+
+        visited = new boolean[N+1];
+        bfs(V);
+    }
+
+    static void dfs(int v){
+        visited[v] = true;
+        System.out.print(v + " ");
+
+        for(int next : graph[v]){
+            if(!visited[next]){
+                dfs(next);
+            }
+        }
+
+    }
+    static void bfs(int start){
+        Queue<Integer> q = new LinkedList<>();
+        q.offer(start);
+        visited[start] = true;
+
+        while(!q.isEmpty()){
+
+            int cur = q.poll();
+            System.out.print(cur + " ");
+
+            for(int next : graph[cur]){
+                if(!visited[next]){
+                    visited[next] = true;
+                    q.offer(next);
+                }
+            }
+        }
+    }
+}

week37/이상억/backjoon/줄_세우기.java

@@ -0,0 +1,60 @@
+import java.util.*;
+import java.io.*;
+
+public class Main {
+
+    static int N, M;
+    static List<Integer>[] graph;
+    static int[] indegree;
+
+    public static void main(String[] args) throws IOException {
+
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+
+        graph = new ArrayList[N + 1];
+        indegree = new int[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());
+
+            // A -> B
+            graph[A].add(B);
+            indegree[B]++;
+        }
+
+        bfs();
+    }
+
+    static void bfs() {
+        Queue<Integer> q = new LinkedList<>();
+
+        // 위상이 0 인 애 부터 줄을 선다.
+        for (int i = 1; i <= N; i++) {
+            if (indegree[i] == 0) {
+                q.offer(i);
+            }
+        }
+
+        while (!q.isEmpty()) {
+            int cur = q.poll();
+            System.out.print(cur + " ");
+
+            for (int next : graph[cur]) {
+                indegree[next]--;
+                if (indegree[next] == 0) {
+                    q.offer(next);
+                }
+            }
+        }
+    }
+}

week37/이상억/backjoon/터렛.java

@@ -0,0 +1,55 @@
+// (1) 같은 원 -1
+// (2) 교점이 없음 0
+// (3) 원 안에 원 0
+// (4) 한 점에서 만남 1
+// (5) 두 점에서 만남
+
+import java.util.*;
+import java.io.*;
+
+public class Main{
+    public static void main(String[] args) throws IOException{
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringBuilder sb = new StringBuilder();
+
+        int N = Integer.parseInt(br.readLine());
+
+        for(int i = 0; i < N; i++){
+            StringTokenizer st = new StringTokenizer(br.readLine());
+
+            int x1 = Integer.parseInt(st.nextToken());
+            int y1 = Integer.parseInt(st.nextToken());
+            int r1 = Integer.parseInt(st.nextToken());
+
+            int x2 = Integer.parseInt(st.nextToken());
+            int y2 = Integer.parseInt(st.nextToken());
+            int r2 = Integer.parseInt(st.nextToken());
+
+            int result = circle_option(x1, y1, r1 , x2, y2, r2);
+            sb.append(result).append('\n');
+        }
+        System.out.print(sb);
+    }
+
+    public static int circle_option(int x1, int y1, int r1, int x2, int y2, int r2){
+
+        int dx = x1 - x2;
+        int dy = y1 - y2;
+        int d = dx*dx + dy*dy;
+
+        int sum = r1 + r2;
+        int diff = Math.abs(r1 - r2);
+
+        if (d == 0 && r1 == r2) {
+            return -1;
+        } else if (d > sum*sum) {
+            return 0;
+        } else if (d < diff*diff) {
+            return 0;
+        } else if (d == sum*sum || d == diff*diff) {
+            return 1;
+        } else {
+            return 2;
+        }
+    }
+}

week37/이상억/backjoon/파일_합치기3.java

@@ -0,0 +1,41 @@
+import java.util.*;
+import java.io.*;
+
+public class Main {
+
+    static int T;
+    static int K;
+
+    public static void main(String[] args) throws IOException {
+
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st;
+
+        T = Integer.parseInt(br.readLine());
+
+        for (int t = 0; t < T; t++) {
+
+            PriorityQueue<Long> pq = new PriorityQueue<>();
+
+            K = Integer.parseInt(br.readLine());
+            st = new StringTokenizer(br.readLine());
+
+            for (int i = 0; i < K; i++) {
+                pq.offer(Long.parseLong(st.nextToken()));
+            }
+
+            long sum = 0;
+
+            while (pq.size() > 1) {
+                long a = pq.poll();
+                long b = pq.poll();
+
+                long part = a + b;
+                sum += part;
+                pq.offer(part);
+            }
+
+            System.out.println(sum);
+        }
+    }
+}