aboutsummaryrefslogtreecommitdiffstats
path: root/src/algorithms/searching/MultiinterpolationSearch.java
blob: 37cb37fc48c4dcd59af450b7fe26f2b3e6422bc0 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
/**
 * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package algorithms.searching;

import java.util.*;
import java.math.*;


/**
 * Multiinterpolation search class. This algorithm is exactly to
 * interpolation search as multibinary search is to binary search.
 * 
 * This algorithm was devised by Mattias Andrée in January of 2014.
 */
public class MultiinterpolationSearch
{
£>for T in char byte short int long float double BigInteger BigDecimal; do . src/comparable
    /**
     * Find the indices of multiple items in a list
     * 
     * @param   items  Sorted list of unique items for which to search
     * @param   array  Sorted list in which to search
     * @return         Two arrays of integer arrays, the 0:th being the indices
     *                 of items, the 1:th being their positions. That is,
     *                 two separate arrays, not and array of pairs. The expected
     *                 position is returned inverted if it was not found, the
     *                 position it whould have upon be inserted, otherwise the
     *                 position is returned as an index.
     */
    public static £(fun "long[][]" indexOf "${T}[] items, ${Tarray} array")
    {
	return indexOf(items, array, 0, array.length - 1£{Targ_name});
    }
    
    /**
     * Find the indices of multiple items in a list
     * 
     * @param   items  Sorted list of unique items for which to search
     * @param   array  Sorted list in which to search
     * @param   start  The index of the first position to search in the array
     * @return         Two arrays of integer arrays, the 0:th being the indices
     *                 of items, the 1:th being their positions. That is,
     *                 two separate arrays, not and array of pairs. The expected
     *                 position is returned inverted if it was not found, the
     *                 position it whould have upon be inserted, otherwise the
     *                 position is returned as an index.
     */
    public static £(fun "long[][]" indexOf "${T}[] items, ${Tarray} array, int start")
    {
	return indexOf(items, array, start, array.length - 1£{Targ_name});
    }
    
    /**
     * Find the indices of multiple items in a list
     * 
     * @param   items  Sorted list of unique items for which to search
     * @param   array  Sorted list in which to search
     * @param   start  The index of the first position to search in the array
     * @param   end    The index after the last position to search in the array
     * @return         Two arrays of integer arrays, the 0:th being the indices
     *                 of items, the 1:th being their positions. That is,
     *                 two separate arrays, not and array of pairs. The expected
     *                 position is returned inverted if it was not found, the
     *                 position it whould have upon be inserted, otherwise the
     *                 position is returned as an index.
     */
    public static £(fun "long[][]" indexOf "${T}[] items, ${Tarray} array, int start, int end")
    {
	int m = items.length, lb_m = 1;
	long[][] rc = new long[2][m];
	
	if (m == 0)
	    return rc;
	
	if ((m & 0xFFFF0000) != 0)  { lb_m |= 16;  m >>= 16; }
	if ((m & 0x0000FF00) != 0)  { lb_m |=  8;  m >>=  8; }
	if ((m & 0x000000F0) != 0)  { lb_m |=  4;  m >>=  4; }
	if ((m & 0x0000000C) != 0)  { lb_m |=  2;  m >>=  2; }
	if ((m & 0x00000002) != 0)  { lb_m +=  1; }
	
        int[][] minomax = new int[4][lb_m];
	m = items.length - 1;
	
	int rc_i = 0;
	int mm_i = 0;
	int imin, imax, amin = 0, amax = 0, lastimax, lastamax;
	
	minomax[0][mm_i] = 0;
	minomax[1][mm_i] = m;
	minomax[2][mm_i] = start;
	minomax[3][mm_i++] = end - 1;
	
£>interpol_search="InterpolationSearch.indexOf(items[imax], array, amin, amax${Targ_name})"
	
	while (mm_i-- > 0)
	{
	    imin = minomax[0][mm_i];
	    imax = minomax[1][mm_i];
	    amin = minomax[2][mm_i];
	    amax = minomax[3][mm_i];
	    
	    while (imax != imin)
	    {
		lastimax = imax;
		lastamax = amax;
		rc[0][rc_i] = imax = imin + ((imax - imin) >>> 1);
		rc[1][rc_i++] = amax = (int)(£{interpol_search});
		if (amax < 0)
		    amax = ~amax;
		
		minomax[0][mm_i] = imax + 1;
		minomax[1][mm_i] = lastimax;
		minomax[2][mm_i] = amax + 1;
		minomax[3][mm_i++] = lastamax;
	    }
	}
	
	imax = m;
	amax = (int)(£{interpol_search});
	rc[0][rc_i] = imax;
	rc[1][rc_i++] = amax;
	
	return rc;
    }
£>done
}