solved 이분그래프 - 396ms 67836KB

Baekjoon/이분그래프/이분그래프_최지수.java

@@ -0,0 +1,67 @@
+import java.util.*;
+import java.io.*;
+
+public class Main {
+    static StringBuilder sb = new StringBuilder();
+
+    static List<Integer>[] map;
+    static int[] arr;
+
+    static boolean ok = true;
+
+    static boolean dfs(int start) {
+        ArrayDeque<Integer> que = new ArrayDeque<>();
+        que.add(start);
+        arr[start] = 1;
+
+        while (!que.isEmpty()) {
+            int now = que.poll();
+            for (int i : map[now]) {
+                if (arr[i] == arr[now]) return false;
+                else if (arr[i] == 0) {
+                    arr[i] = (~arr[now]) & 3;
+                    que.add(i);
+                }
+            }
+        }
+
+        return true;
+    }
+
+    static int read() throws IOException {
+        int c, n = System.in.read() & 15;
+        while ((c = System.in.read()) > 32) {
+            n = (n << 3) + (n << 1) + (c & 15);
+        }
+        return n;
+    }
+
+    static void mapSetting(int one, int two) {
+        map[one].add(two);
+        map[two].add(one);
+    }
+
+    public static void main(String[] args) throws IOException {
+
+        int T = read();
+
+        for (int t = 0; t < T; t++) {
+            int v = read();
+            int e = read();
+            arr = new int[v+1];
+            map = new ArrayList[v+1];
+            ok = true;
+            for (int i = 1; i <= v; i++) map[i] = new ArrayList<>();
+            for (int i = 0; i < e; i++) mapSetting(read(), read());
+
+            for (int i = 1; i < v+1 && ok; i++) {
+                if (arr[i] != 0) continue;
+                ok &= dfs(i);
+            }
+            sb.append(ok ? "YES\n" : "NO\n");
+        }
+
+        System.out.println(sb.toString());
+    }
+}
+