SPOJ - DICT :: TRIE Tree

online judge solution of trie tree/dictionary_search_by_prefix.cpp

@@ -0,0 +1,90 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+struct node {
+	bool mark;
+	node* next[27];
+	node() {
+		mark = 0;
+		for (int i = 0; i < 26; next[i] = NULL, i++);
+	}
+} *root;
+
+void insert(char* s, int len) {
+	node* cur = root;
+	for (int i = 0; i < len; i++) {
+		int id = s[i] - 'a';
+		if (cur->next[id] == NULL) cur->next[id] = new node();
+		cur = cur->next[id];
+	}
+	cur->mark = 1;
+}
+
+void dfs(char *s, int len, node* cur) {
+	if (cur->mark) printf("%s\n", s);
+	for (int i = 0; i < 26; i++) {
+		if (cur->next[i] != NULL) {
+			s[len + 1] = (i + 'a');
+			s[len + 2] = '\0';
+			dfs(s, len+1, cur->next[i]);
+		}
+	}
+}
+
+bool search(char* s, int len) {
+	node* cur = root;
+	int cnt = 0;
+	for (int i = 0; i < len; i++) {
+		int id = s[i] - 'a';
+		if (cur->next[id] == NULL) return false;
+		cur = cur->next[id];
+	}
+	bool found = false;
+	for (int i = 0; i < 26; i++) {
+		if (cur->next[i] != NULL) {
+			s[len] = (i + 'a');
+			s[len + 1] = '\0';
+			dfs(s, len, cur->next[i]);
+			found = true;
+		}
+	}
+	return found;
+}
+
+int main() {
+	int n, q;
+	char s[30];
+	root = new node();
+	scanf("%d", &n);
+	for (int i = 1; i <= n; i++) scanf("%s", s), insert(s, strlen(s));
+	scanf("%d", &q);
+	for (int i = 1; i <= q; i++) {
+		scanf("%s", s);
+		printf("Case #%d:\n", i);
+		if (!search(s, strlen(s))) printf("No match.\n");
+	}
+	return 0;
+}
+
+/*
+INPUT:
+
+5 :: _____given word
+set
+lol
+setter
+setting
+settings
+2 :: _____query by prefix
+set
+happy
+
+OUTPUT:
+
+Case #1: __ word with prefix 'set'
+setter
+setting
+settings
+Case #2: __ word with prefix 'happy'
+No match.
+*/