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#4 Suffix Arrayの高速化 #38

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Merged
NASU41 merged 7 commits into from
Sep 21, 2020
Merged

#4 Suffix Arrayの高速化 #38

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10a92d1
untracked files on improve-sa: c13664f MathLibrary
Sep 20, 2020
ca94592
index on improve-sa: c13664f MathLibrary
Sep 20, 2020
34bf618
WIP on improve-sa: c13664f MathLibrary
Sep 20, 2020
03f55f4
Merge branch 'master' into StringAlgorithm
Sep 20, 2020
0123f59
'saNaiveとsaDoublingを高速化。しきい値調整。'
Sep 20, 2020
8379f21
'int[]版suffix arrayの座標圧縮を高速化'
Sep 20, 2020
a61a88d
'不要なファイルを削除'
Sep 20, 2020
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105 changes: 69 additions & 36 deletions StringAlgorithm/StringAlgorithm.java
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Original file line number Diff line number Diff line change
@@ -1,62 +1,95 @@
import java.util.Arrays;

class StringAlgorithm {
private static int[] saNaive(int[] s) {
int n = s.length;
Integer[] _sa = new Integer[n];
for (int i = 0; i < n; i++) {
_sa[i] = i;
int[] sa = new int[n];
for(int i = 0;i < n;i++){
sa[i] = i;
}
java.util.Arrays.sort(_sa, (l, r) -> {
insertionsortUsingComparator(sa, (l, r) -> {
while (l < n && r < n) {
if (s[l] != s[r]) return s[l] - s[r];
l++;
r++;
}
return -(l - r);
});
int[] sa = new int[n];
for (int i = 0; i < n; i++) {
sa[i] = _sa[i];
}
return sa;
}

private static int[] saDoubling(int[] s) {
int n = s.length;
Integer[] _sa = new Integer[n];
for (int i = 0; i < n; i++) {
_sa[i] = i;
int[] sa = new int[n];
for(int i = 0;i < n;i++){
sa[i] = i;
}
int[] rnk = s;
int[] tmp = new int[n];

for (int k = 1; k < n; k *= 2) {
final int _k = k;
final int[] _rnk = rnk;
java.util.Comparator<Integer> cmp = (x, y) -> {
java.util.function.IntBinaryOperator cmp = (x, y) -> {
if (_rnk[x] != _rnk[y]) return _rnk[x] - _rnk[y];
int rx = x + _k < n ? _rnk[x + _k] : -1;
int ry = y + _k < n ? _rnk[y + _k] : -1;
return rx - ry;
};
java.util.Arrays.sort(_sa, cmp);
tmp[_sa[0]] = 0;
mergesortUsingComparator(sa, cmp);
tmp[sa[0]] = 0;
for (int i = 1; i < n; i++) {
tmp[_sa[i]] = tmp[_sa[i - 1]] + (cmp.compare(_sa[i - 1], _sa[i]) < 0 ? 1 : 0);
tmp[sa[i]] = tmp[sa[i - 1]] + (cmp.applyAsInt(sa[i - 1], sa[i]) < 0 ? 1 : 0);
}
int[] buf = tmp;
tmp = rnk;
rnk = buf;
}
return sa;
}

int[] sa = new int[n];
for (int i = 0; i < n; i++) {
sa[i] = _sa[i];
private static void insertionsortUsingComparator(int[] a, java.util.function.IntBinaryOperator comparator) {
final int n = a.length;
for (int i = 1; i < n; i++) {
final int tmp = a[i];
if (comparator.applyAsInt(a[i - 1], tmp) > 0) {
int j = i;
do {
a[j] = a[j - 1];
j--;
} while (j > 0 && comparator.applyAsInt(a[j - 1], tmp) > 0);
a[j] = tmp;
}
}
return sa;
}

private static final int THRESHOLD_NAIVE = 10;
private static final int THRESHOLD_DOUBLING = 40;
private static void mergesortUsingComparator(int[] a, java.util.function.IntBinaryOperator comparator) {
final int n = a.length;
final int[] work = new int[n];
for (int block = 1; block <= n; block <<= 1) {
final int block2 = block << 1;
for (int l = 0, max = n - block; l < max; l += block2) {
int m = l + block;
int r = Math.min(l + block2, n);
System.arraycopy(a, l, work, 0, block);
for (int i = l, wi = 0, ti = m;; i++) {
if (ti == r) {
System.arraycopy(work, wi, a, i, block - wi);
break;
}
if (comparator.applyAsInt(work[wi], a[ti]) > 0) {
a[i] = a[ti++];
} else {
a[i] = work[wi++];
if (wi == block) break;
}
}
}
}
}

private static final int THRESHOLD_NAIVE = 50;
private static final int THRESHOLD_DOUBLING = 0;

private static int[] sais(int[] s, int upper) {
int n = s.length;
Expand All @@ -72,9 +105,9 @@ private static int[] sais(int[] s, int upper) {
if (n < THRESHOLD_NAIVE) {
return saNaive(s);
}
if (n < THRESHOLD_DOUBLING) {
return saDoubling(s);
}
// if (n < THRESHOLD_DOUBLING) {
// return saDoubling(s);
// }

int[] sa = new int[n];
boolean[] ls = new boolean[n];
Expand Down Expand Up @@ -195,22 +228,22 @@ public static int[] suffixArray(int[] s, int upper) {
return sais(s, upper);
}

public static int[] suffixArray(int[] s) {
public static int[] suffixArray(int[] s)
{
int n = s.length;
Integer[] idx = new Integer[n];
for (int i = 0; i < n; i++) {
idx[i] = i;
int[] vals = Arrays.copyOf(s, n);
java.util.Arrays.sort(vals);
int p = 1;
for(int i = 1;i < n;i++){
if(vals[i] != vals[i-1]){
vals[p++] = vals[i];
}
}
java.util.Arrays.sort(idx, (l, r) -> s[l] - s[r]);
int[] s2 = new int[n];
int now = 0;
for (int i = 0; i < n; i++) {
if (i > 0 && s[idx[i - 1]] != s[idx[i]]) {
now++;
}
s2[idx[i]] = now;
for(int i = 0;i < n;i++){
s2[i] = java.util.Arrays.binarySearch(vals, 0, p, s[i]);
}
return sais(s2, now);
return sais(s2, p);
}

public static int[] suffixArray(char[] s) {
Expand Down