后缀自动机（未验证正确性）

Author: Dev-XYS

Suffix-Automaton.cpp

@@ -0,0 +1,71 @@
+#include <cstdio>
+#include <cstring>
+
+#define NIL 0
+#define ALPHABET_SIZE 26
+
+using namespace std;
+
+struct node
+{
+	node *next[ALPHABET_SIZE], *parent;
+	int len;
+	node(int _len = 0) : len(_len) { memset(next, 0, sizeof(next)), parent = NIL; }
+}*root, *last;
+
+char s[100000];
+int len;
+
+void init()
+{
+	root = new node(0);
+	last = root;
+}
+
+void extend(int x)
+{
+	node *p = last;
+	node *np = new node(p->len + 1);
+	while (p != NIL && p->next[x] == NIL)
+	{
+		p->next[x] = np;
+		p = p->parent;
+	}
+	if (p == NIL)
+	{
+		np->parent = root;
+	}
+	else
+	{
+		node *q = p->next[x];
+		if (q->len == p->len + 1)
+		{
+			np->parent = q;
+		}
+		else
+		{
+			node *nq = new node;
+			*nq = *q;
+			nq->len = p->len + 1;
+			q->parent = np->parent = nq;
+			while (p != NIL && p->next[x] == q)
+			{
+				p->next[x] = nq;
+				p = p->parent;
+			}
+		}
+	}
+	last = np;
+}
+
+int main()
+{
+	scanf("%s", s);
+	len = strlen(s);
+	init();
+	for (int i = 0; i < len; i++)
+	{
+		extend(s[i] - 'a');
+	}
+	return 0;
+}