[20251124] BOJ / P3 / XOR 자료구조 / 권혁준

khj20006/202511/24 BOJ P3 XOR 자료구조.md

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+```cpp
+#include <bits/stdc++.h>
+using namespace std;
+
+class Node {
+    public:
+    int cnt;
+    Node *left, *right; // left = 1, right = 0
+
+    Node() {
+        cnt = 0;
+        left = nullptr;
+        right = nullptr;
+    }
+};
+
+class Trie {
+    Node *root;
+
+    public:
+    Trie() {
+        root = new Node();
+    }
+
+    void insert(int x) {
+        Node *now = root;
+        for(int dep=25;--dep>=0;) {
+            int bit = x & (1<<dep);
+            if(bit) {
+                if(now->left == nullptr) now->left = new Node();
+                now = now->left;
+            }
+            else {
+                if(now->right == nullptr) now->right = new Node();
+                now = now->right;
+            }
+            now->cnt++;
+        }
+    }
+
+    int find(int x, int tar) {
+        int ret = 0;
+        Node *now = root;
+        for(int dep=25;--dep>=0;) {
+            int bit = x & (1<<dep) ? 1 : 0;
+            int need = bit ^ tar;
+            int res = 0;
+            if(need) {
+                if(now->left == nullptr) now = now->right;
+                else now = now->left, res = (1<<dep);
+            }
+            else {
+                if(now->right == nullptr) now = now->left, res = (1<<dep);
+                else now = now->right;
+            }
+            ret |= res;
+        }
+        return x^ret;
+    }
+
+    int find_min(int x) {
+        return find(x, 0);
+    }
+
+    int find_max(int x) {
+        return find(x, 1);
+    }
+
+    void remove(int x) {
+        Node *now = root;
+        stack<pair<Node *, char>> st;
+        st.emplace(now, 'L');
+        for(int dep=25;--dep>=0;) {
+            int bit = x & (1<<dep);
+            if(bit) {
+                now = now->left;
+                st.emplace(now, 'L');
+            }
+            else {
+                now = now->right;
+                st.emplace(now, 'R');
+            }
+        }
+        bool l = 0, r = 0;
+        while(!st.empty()) {
+            auto cur = st.top(); st.pop();
+            if(l) cur.first->left = nullptr;
+            if(r) cur.first->right = nullptr;
+            l = 0, r = 0;
+            if(!--cur.first->cnt) {
+                cur.first = nullptr;
+                if(cur.second == 'L') l = 1, r = 0;
+                else l = 0, r = 1;
+            }
+        }
+    }
+};
+
+Trie *trie;
+set<int> s;
+
+int add(int x) {
+    if(!s.count(x)) {
+        s.insert(x);
+        trie->insert(x);
+    }
+    return s.size();
+}
+
+int remove_min() {
+    if(s.empty()) return -1;
+    int x = *s.begin();
+    trie->remove(x);
+    s.erase(x);
+    return x;
+}
+
+int remove_max() {
+    if(s.empty()) return -1;
+    int x = *s.rbegin();
+    trie->remove(x);
+    s.erase(x);
+    return x;
+}
+
+int main(){
+    cin.tie(0)->sync_with_stdio(0);
+
+
+    int T;
+    for(cin>>T;T--;) {
+        int N, Q;
+        cin>>N>>Q;
+        trie = new Trie();
+        s = set<int>();
+
+        for(int i=0,x;i<N;i++) {
+            cin>>x;
+            add(x);
+        }
+
+        for(int o,x;Q--;) {
+            int ret = -1;
+            cin>>o;
+            if(o >= 4) {
+                if(o == 4) ret = remove_min();
+                else ret = remove_max();
+            }
+            else {
+                cin>>x;
+                if(o == 1) ret = trie->find_min(x);
+                else if(o == 2) ret = trie->find_max(x);
+                else ret = add(x);
+            }
+
+            cout<<ret<<'\n';
+        }
+    }
+
+}
+```