C#版接尾辞ツリー最長共通列LCS
7581 ワード
いくつかのネット上の接尾辞の木についての文章を見て、多くはC/C++版で、いくつかのバージョンを参照して1つのC#版をつづったことを発見しました.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace test_file
{
class fix
{
private void swap(ref int[] x, ref int[] y)
{
int[] temp = x;
x = y;
y = x;
}
const int MAXN = 500005;
//using namespace std;
int[] r = new int[MAXN];
int[] wa = new int[MAXN];
int[] wb = new int[MAXN];
int[] wv = new int[MAXN];
int[] tmp = new int[MAXN];
int[]sa = new int[MAXN];
private bool cmp(int [] r, int a, int b, int l)
{
return r[a] == r[b] && r[a + l] == r[b + l];
}
/// <summary>
///
/// </summary>
/// <param name="r"></param>
/// <param name="sa"> r 、 </param>
/// <param name="n"> r </param>
/// <param name="m"> 1</param>
public void da(int []r, int []sa, int n, int m)
{
int i, j, p;
int [] x = wa; int [] y = wb ; int []ws = tmp;
int[] t;
for (i = 0; i < m; i++) ws[i] = 0;
for (i = 0; i < n; i++) ws[x[i] = r[i]]++;
for (i = 1; i < m; i++) ws[i] += ws[i - 1];
for (i = n - 1; i >= 0; i--)sa[--ws[x[i]]] = i;
for (j = 1, p = 1; p < n; j *= 2, m = p) // 2 K rank
{
for (p = 0, i = n - j; i < n; i++)y[p++] = i;
for (i = 0; i < n; i++)if (sa[i] >= j) y[p++] = sa[i] - j;
for (i = 0; i < n; i++) wv[i] = x[y[i]];
for (i = 0; i < m; i++) ws[i] = 0;
for (i = 0; i < n; i++) ws[wv[i]]++;
for (i = 1; i < m; i++) ws[i] += ws[i - 1];
for (i = n - 1; i >= 0; i--) sa[--ws[wv[i]]] = y[i];
for (t = x, x = y, y = t, p = 1, x[sa[0]] = 0, i = 1; i < n; i++)
x[sa[i]] = cmp(y, sa[i - 1], sa[i], j) ? p - 1 : p++;
}
}
int [] rank = new int [MAXN];
private int [] height = new int[MAXN];
public void calheight(int [] r,int []sa,int n)
{
int i,j,k=0;
for(i=1;i<=n;i++)
rank[sa[i]]=i;
for(i=0;i<n;height[rank[i++]]=k)
{
if(k > 0) k--;
else k = 0;
for(j = sa[rank[i] -1]; r[i+k] == r[j+k] ; k++);
}
return;
}
int[] belong = new int[MAXN];
int VISIT_LEN = 5000;
private bool ok(int A,int n, int m ,int [] sa)
{
int i,j,k;
bool [] ba = new bool [VISIT_LEN];
for (i=1;i<=n;i++)
{
if (height[i]>=A)
{
for (j=i;height[j]>=A && j<=n;j++);
j--;
for (int nd = 0; nd < VISIT_LEN; nd++)
{
ba[nd] = false;
}
for (k=i-1;k<=j;k++)
ba[belong[sa[k]]]=true;
for (k=0;ba[k] && k<n;k++);
if (k==m)
return true;
i=j;
}
}
return false;
}
/// <summary>
///
/// </summary>
/// <param name="n"> </param>
/// <param name="m"> </param>
/// <param name="arr"> </param>
/// <returns></returns>
private int binarySearch(int n , int m,int []arr)
{
int l = 0, r = n;
int mid;
while (l +1 < r)
{
mid = (l + r)/2;
if (ok(mid,n,m,arr))
l = mid;
else r = mid - 1;
}
if (ok(r, n, m, arr))
l = r;
return l;
}
/// <summary>
///
/// </summary>
/// <param name="str"> </param>
/// <returns></returns>
public string get_LCS(string[] str)
{
string ss = null;
//int str_max_length = 0;
int mark = 0; int char_len = 0;
foreach (string s in str)
{
ss += s;
char[] temp = s.ToCharArray();
for(int i = 0 ; i < temp.Length ; i++)
{
belong[char_len++] = mark;
}
char_len++;
ss += (char)(0xFD9B + (mark++)); // 。 （str1 * str2 * str 3 * .....* strn *） *
}
int m = 0, n = ss.Length;
int[] r = new int[ss.Length + 1];
int[] saa = new int[ss.Length + 1];
char[] chars = ss.ToCharArray();
for (int i = 0; i < chars.Length; i++)
{
r[i] = (int)chars[i];
m = m > (int)chars[i] ? m : (int)chars[i];
}
r[n] = 0;
da(r, saa, n + 1, m + 1);
calheight(r, saa, ss.Length);
int resu = binarySearch(ss.Length, mark,saa);
if(resu > 0)
return get_ndx(resu , n , str.Length , chars,saa);
else
return "none";
}
/// <summary>
///
/// </summary>
/// <param name="len"> </param>
/// <param name="n"> </param>
/// <param name="m"> </param>
/// <param name="s"> </param>
/// <param name="sa">sa ， “ ”</param>
/// <returns></returns>
private string get_ndx(int len , int n , int m , char [] s,int [] sa)
{
//outset.clear();
StringBuilder result = new StringBuilder();
bool[] visit = new bool[VISIT_LEN];
int count=0;
for(int i=1;i<n;i++)
{
if(height[i+1]<len)
{
if(count>0)
{
if(count>m/2)
{
for(int j=0,index=sa[i];j<len;j++)
result.Append(s[j+index]);
result.Append("α");
}
count=0;
for (int ii = 0; ii < VISIT_LEN; ii++)
{
visit[ii] = false;
}
}
}
else
{
if(!visit[belong[sa[i]]])
{
visit[belong[sa[i]]]=true ;
count++;
}
if(!visit[belong[sa[i+1]]])
{
visit[belong[sa[i+1]]]=true;
count++;
}
}
}
return result.ToString();
}
}
}