Trie (prefix_tree/radix_tree)

radix_tree.cpp

@@ -0,0 +1,61 @@
+// Radix tree
+
+#include <bits/stdc++.h>
+using namespace std;
+
+struct node {
+	bool isWord;
+	node* next[26+1];
+
+	node() {
+		isWord = false;
+		for (int i = 0; i < 26; next[i] = NULL, i++);
+	}
+} * root;
+
+void insert(char* str, int len) {
+    node* cur = root;
+    for (int i = 0; i < len; i++) {
+		int id = str[i] - 'a';
+		if (cur->next[id] == NULL) cur->next[id] = new node();
+		cur = cur->next[id];
+    }
+    cur->isWord = true;
+}
+
+bool search(char* str, int len) {
+	node* cur = root;
+	for (int i = 0; i < len; i++) {
+			int id = str[i] - 'a';
+			if (cur->next[id] == NULL) return false;
+			cur = cur->next[id];
+	}
+	return cur->isWord;
+}
+
+void del(node* cur) {
+	for (int i = 0; i < 26; i++)
+			if (cur->next[i]) del(cur->next[i]);
+	delete(cur);
+}
+
+int main() {
+	int n, q;
+	root = new node();
+	puts("Enter number of words:");
+	scanf("%d", &n);
+	for (int i = 0; i < n; i++) {
+		char s[50];
+		scanf("%s", s);
+		insert(s, strlen(s));
+	}
+	puts("Enter number of query:");
+	scanf("%d", &q);
+	for (int i = 0; i < q; i++) {
+		char s[50];
+		scanf("%s", s);
+		if (search(s, strlen(s))) puts("FOUND!");
+		else puts("NOT FOUND!");
+	}
+	return 0;
+}