Create jh.java

Java/BOJ_3830_교수님은 기다리지 않는다/jh.java

@@ -0,0 +1,61 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    static int N, M;
+    static int[] parent, weight;
+
+    public static void main(String[] args) throws Exception {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+        StringTokenizer st;
+
+        do{
+            st = new StringTokenizer(br.readLine());
+            N = Integer.parseInt(st.nextToken());
+            M = Integer.parseInt(st.nextToken());
+
+            parent = new int[N+1];
+            weight = new int[N+1];
+            for (int i = 1; i <= N; i++)
+                parent[i] = i;
+
+            int a, b, w;
+            for (int i = 0; i < M; i++) {
+                st = new StringTokenizer(br.readLine());
+                String t = st.nextToken();
+                a = Integer.parseInt(st.nextToken());
+                b = Integer.parseInt(st.nextToken());
+                if (t.equals("!")){
+                    w = Integer.parseInt(st.nextToken());
+                    union(a, b, w);
+                } else{
+                    if(find(a)==find(b))
+                        bw.write(weight[b]-weight[a]+"\n");
+                    else
+                        bw.write("UNKNOWN\n");
+                }
+            }
+        } while(N!=0 && M!=0);
+
+        bw.flush();
+        bw.close();
+        br.close();
+    }
+    public static void union(int a, int b, int w){
+        int pa = find(a);
+        int pb = find(b);
+        if (pa!=pb){
+            weight[pb] = weight[a] - weight[b] + w;
+            parent[pb] = pa;
+        }
+    }
+    public static int find(int id){
+        if (parent[id]==id)
+            return id;
+        int pid = find(parent[id]);
+        weight[id] += weight[parent[id]];
+        return parent[id] = pid;
+    }
+}