From 16a05f1a38e4d420dbf792686f3a8e71cde06112 Mon Sep 17 00:00:00 2001
From: Ren Baoshuo <i@baoshuo.ren>
Date: Sun, 12 Sep 2021 14:06:27 +0800
Subject: [PATCH] =?UTF-8?q?835.=20Trie=E5=AD=97=E7=AC=A6=E4=B8=B2=E7=BB=9F?=
 =?UTF-8?q?=E8=AE=A1?=
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https://www.acwing.com/problem/content/submission/code_detail/7680320/
---
 AcWing/835/835.cpp | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 AcWing/835/835.cpp

diff --git a/AcWing/835/835.cpp b/AcWing/835/835.cpp
new file mode 100644
index 00000000..aabe369c
--- /dev/null
+++ b/AcWing/835/835.cpp
@@ -0,0 +1,46 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int n;
+char op;
+string s;
+
+struct node {
+    int val;
+    node* next[30];
+
+    ~node() {
+        for (auto i : next) {
+            delete i;
+        }
+    }
+};
+
+void insert(node* root, string s) {
+    if (s.empty()) {
+        root->val++;
+        return;
+    }
+    if (root->next[s[0] - 'a'] == nullptr) root->next[s[0] - 'a'] = new node();
+    insert(root->next[s[0] - 'a'], s.substr(1));
+}
+
+int query(node* root, string s) {
+    return s.empty() ? root->val : (root->next[s[0] - 'a'] == nullptr ? 0 : query(root->next[s[0] - 'a'], s.substr(1)));
+}
+
+int main() {
+    node* root = new node();
+    cin >> n;
+    for (int i = 0; i < n; i++) {
+        cin >> op >> s;
+        if (op == 'I') {
+            insert(root, s);
+        } else {
+            cout << query(root, s) << endl;
+        }
+    }
+    delete root;
+    return 0;
+}