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authorJSDurand <mmemmew@gmail.com>2021-01-13 13:01:34 +0800
committerJSDurand <mmemmew@gmail.com>2021-01-13 13:01:34 +0800
commit3666deaed5b0baf0a74f14db5872105c9e7865f9 (patch)
tree3535c3f57ed9d5b1cd4e3e81831f627840b6e81b /suffix tree/ST.cpp
parent1700588e1a3cfb5fa45fb64393c68782bc35fc38 (diff)
A temporary intermeidate step
Now I got almost every functionality that we need, including pdf, mu4e, magit, et cetera.
Diffstat (limited to 'suffix tree/ST.cpp')
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1 files changed, 131 insertions, 0 deletions
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+/**
+ * Copyright (c) 2016 Sergey Makagonov
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#include <iostream>
+#include <stdio.h>
+#include <string>
+
+const int oo = 1<<25;
+const int ALPHABET_SIZE = 256;
+const int MAXN = 5000;
+
+using namespace std;
+
+int root, last_added, pos, needSL, remainder,
+ active_node, active_e, active_len;
+
+struct node {
+/*
+ There is no need to create an "Edge" struct.
+ Information about the edge is stored right in the node.
+ [start; end) interval specifies the edge,
+ by which the node is connected to its parent node.
+*/
+
+ int start, end, slink;
+ int next[ALPHABET_SIZE];
+
+ int edge_length() {
+ return min(end, pos + 1) - start;
+ }
+};
+
+node tree[2*MAXN];
+char text[MAXN];
+
+int new_node(int start, int end = oo) {
+ node nd;
+ nd.start = start;
+ nd.end = end;
+ nd.slink = 0;
+ for (int i = 0; i < ALPHABET_SIZE; i++)
+ nd.next[i] = 0;
+ tree[++last_added] = nd;
+ return last_added;
+}
+
+char active_edge() {
+ return text[active_e];
+}
+
+void add_SL(int node) {
+ if (needSL > 0) tree[needSL].slink = node;
+ needSL = node;
+}
+
+bool walk_down(int node) {
+ if (active_len >= tree[node].edge_length()) {
+ active_e += tree[node].edge_length();
+ active_len -= tree[node].edge_length();
+ active_node = node;
+ return true;
+ }
+ return false;
+}
+
+void st_init() {
+ needSL = 0, last_added = 0, pos = -1,
+ remainder = 0, active_node = 0, active_e = 0, active_len = 0;
+ root = active_node = new_node(-1, -1);
+}
+
+void st_extend(char c) {
+ text[++pos] = c;
+ needSL = 0;
+ remainder++;
+ while(remainder > 0) {
+ if (active_len == 0) active_e = pos;
+ if (tree[active_node].next[active_edge()] == 0) {
+ int leaf = new_node(pos);
+ tree[active_node].next[active_edge()] = leaf;
+ add_SL(active_node); //rule 2
+ } else {
+ int nxt = tree[active_node].next[active_edge()];
+ if (walk_down(nxt)) continue; //observation 2
+ if (text[tree[nxt].start + active_len] == c) { //observation 1
+ active_len++;
+ add_SL(active_node); //observation 3
+ break;
+ }
+ int split = new_node(tree[nxt].start, tree[nxt].start + active_len);
+ tree[active_node].next[active_edge()] = split;
+ int leaf = new_node(pos);
+ tree[split].next[c] = leaf;
+ tree[nxt].start += active_len;
+ tree[split].next[text[tree[nxt].start]] = nxt;
+ add_SL(split); //rule 2
+ }
+ remainder--;
+ if (active_node == root && active_len > 0) { //rule 1
+ active_len--;
+ active_e = pos - remainder + 1;
+ } else
+ active_node = tree[active_node].slink > 0 ? tree[active_node].slink : root; //rule 3
+ }
+}
+
+int main() {
+ //
+ return 0;
+}