原始的后缀数组（附CodeVS - 1500 后缀排序代码）

Author: Dev-XYS

Suffix-Array(Doubling).cpp

@@ -0,0 +1,114 @@
+#include <cstdio>
+#include <cstring>
+
+#define STRING_LENGTH 100000
+
+using namespace std;
+
+struct sortinfo
+{
+	int x, y, ord;
+};
+
+int l;
+char s[STRING_LENGTH];
+int rank[STRING_LENGTH * 2], sa[STRING_LENGTH];
+
+inline bool operator == (const sortinfo &x, const sortinfo &y)
+{
+	return x.x == y.x && x.y == y.y;
+}
+
+void radix_sort(sortinfo *d)
+{
+	static sortinfo _d[STRING_LENGTH], res[STRING_LENGTH];
+	static int c[STRING_LENGTH];
+	memset(c, 0, sizeof(c));
+	for (int i = 0; i < l; i++)
+	{
+		c[d[i].y]++;
+	}
+	for (int i = 1; i <= l; i++)
+	{
+		c[i] += c[i - 1];
+	}
+	for (int i = l - 1; i >= 0; i--)
+	{
+		_d[--c[d[i].y]] = d[i];
+	}
+	memset(c, 0, sizeof(c));
+	for (int i = 0; i < l; i++)
+	{
+		c[_d[i].x]++;
+	}
+	for (int i = 1; i <= l; i++)
+	{
+		c[i] += c[i - 1];
+	}
+	for (int i = l - 1; i >= 0; i--)
+	{
+		res[--c[_d[i].x]] = _d[i];
+	}
+	for (int i = 0; i < l; i++)
+	{
+		d[i] = res[i];
+	}
+}
+
+void init_rank()
+{
+	static int c[256];
+	static sortinfo d[STRING_LENGTH];
+	int x = 1;
+	for (int i = 0; i < l; i++)
+	{
+		c[(int)s[i]] = 1;
+	}
+	for (int i = 0; i < 256; i++)
+	{
+		if (c[i] == 1)
+		{
+			c[i] = x++;
+		}
+	}
+	for (int i = 0; i < l; i++)
+	{
+		rank[i] = c[(int)s[i]];
+	}
+	for (int k = 1; k < l; k <<= 1)
+	{
+		for (int i = 0; i < l; i++)
+		{
+			d[i].x = rank[i];
+			d[i].y = rank[i + k];
+			d[i].ord = i;
+		}
+		radix_sort(d);
+		x = 1;
+		rank[d[0].ord] = 1;
+		for (int i = 1; i < l; i++)
+		{
+			rank[d[i].ord] = (d[i] == d[i - 1] ? x : ++x);
+		}
+	}
+}
+
+void rank_to_sa()
+{
+	for (int i = 0; i < l; i++)
+	{
+		sa[rank[i] - 1] = i + 1;
+	}
+}
+
+int main()
+{
+	scanf("%d%s", &l, s);
+	init_rank();
+	rank_to_sa();
+	for (int i = 0; i < l; i++)
+	{
+		printf("%d\n", sa[i]);
+	}
+	return 0;
+}