From 45e68c4f554e24cf3eac7ff8b65808a3349d459d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=ED=99=A9=EC=A0=95=ED=9B=88=20=28Hwang=20JungHun=29?=
 <anthony9307@naver.com>
Date: Tue, 10 Aug 2021 15:47:10 +0900
Subject: [PATCH] Create jh.java

---
 .../jh.java"                                  | 61 +++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 "Java/BOJ_3830_\352\265\220\354\210\230\353\213\230\354\235\200 \352\270\260\353\213\244\353\246\254\354\247\200 \354\225\212\353\212\224\353\213\244/jh.java"

diff --git "a/Java/BOJ_3830_\352\265\220\354\210\230\353\213\230\354\235\200 \352\270\260\353\213\244\353\246\254\354\247\200 \354\225\212\353\212\224\353\213\244/jh.java" "b/Java/BOJ_3830_\352\265\220\354\210\230\353\213\230\354\235\200 \352\270\260\353\213\244\353\246\254\354\247\200 \354\225\212\353\212\224\353\213\244/jh.java"
new file mode 100644
index 0000000..71845fc
--- /dev/null
+++ "b/Java/BOJ_3830_\352\265\220\354\210\230\353\213\230\354\235\200 \352\270\260\353\213\244\353\246\254\354\247\200 \354\225\212\353\212\224\353\213\244/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;
+    }
+}