[20250211] BOJ / 플래3 / XOR 합 / 권혁준

Author: oncsr

khj20006/202502/11 BOJ P3 XOR 합.md

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+```java
+
+import java.util.*;
+import java.io.*;
+
+class Node{
+	int d;
+	Node l, r;
+	Node(int d){this.d = d;}
+}
+
+class Trie{
+	Node root;
+	Trie(){root = new Node(31);}
+	void insert(int x) {
+		Node now = root;
+		for(int i=30;i>=0;i--) {
+			int bit = x & (1<<i);
+			x -= bit;
+			if(bit == 0) {
+				if(now.l == null) now.l = new Node(i);
+				now = now.l;
+			}
+			else {
+				if(now.r == null) now.r = new Node(i);
+				now = now.r;
+			}
+		}
+	}
+	// x 와 xor했을 때 가장 큰 값 찾기
+	int find(int x) {
+		Node now = root;
+		int res = 0;
+		for(int i=30;i>=0;i--) {
+			int bit = x & (1<<i);
+			if(bit != 0) {
+				if(now.l == null) now = now.r;
+				else {
+					res += (1<<i);
+					now = now.l;
+				}
+			}
+			else {
+				if(now.r == null) now = now.l;
+				else {
+					res += (1<<i);
+					now = now.r;
+				}
+			}
+		}
+		return res;
+	}
+}
+
+class Main {
+	
+	// IO field
+	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+	static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+	static StringTokenizer st;
+
+	static void nextLine() throws Exception {st = new StringTokenizer(br.readLine());}
+	static int nextInt() {return Integer.parseInt(st.nextToken());}
+	static long nextLong() {return Long.parseLong(st.nextToken());}
+	static void bwEnd() throws Exception {bw.flush();bw.close();}
+	
+	// Additional field
+	static Trie trie;
+	static int T, N;
+	static int[] S;
+	
+	
+	public static void main(String[] args) throws Exception {
+		
+		ready();
+		//solve();
+	
+		bwEnd();
+	}
+	
+	static void ready() throws Exception{
+
+		T = Integer.parseInt(br.readLine());
+		while(T-- > 0) {
+			trie = new Trie();
+			
+			N = Integer.parseInt(br.readLine());
+			S = new int[N+1];
+
+			nextLine();
+			for(int i=1;i<=N;i++) {
+				S[i] = nextInt();
+				S[i] ^= S[i-1];
+			}
+			solve();
+		}
+		
+	}
+	
+	static void solve() throws Exception{
+		
+		for(int i=1;i<=N;i++) trie.insert(S[i]);
+		
+		int ans = 0;
+		for(int i=0;i<N;i++) ans = Math.max(ans, trie.find(S[i]));
+		bw.write(ans+"\n");
+		
+	}
+	
+	
+}
+
+```