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Copy pathsuffixarray.h
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144 lines (134 loc) · 3.61 KB
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Copy pathsuffixarray.h
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144 lines (134 loc) · 3.61 KB
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template<class Str>
struct SA {
Str s;
V<int> sa, rsa, lcp;
SA() {}
SA(Str s, V<int> sa) : s(s), sa(sa) {
int n = int(s.size());
// make rsa
rsa = V<int>(n+1);
for (int i = 0; i <= n; i++) {
rsa[sa[i]] = i;
}
// make lcp
lcp = V<int>(n);
int h = 0;
for (int i = 0; i < n; i++) {
int j = sa[rsa[i]-1];
if (h > 0) h--;
for (; j+h < n && i+h < n; h++) {
if (s[j+h] != s[i+h]) break;
}
lcp[rsa[i]-1] = h;
}
}
};
template<class Str>
V<int> sa_is(Str s, int B = 200) {
int n = int(s.size());
V<int> sa(n+1);
if (n == 0) return sa;
for (int i = 0; i < n; i++) s[i]++;
s.push_back(0); B++;
V<bool> ls(n+1);
ls[n] = true;
for (int i = n-1; i >= 0; i--) {
ls[i] = (s[i] == s[i+1]) ? ls[i+1] : (s[i] < s[i+1]);
}
V<int> sum_l(B+1), sum_s(B+1);
for (int i = 0; i <= n; i++) {
if (!ls[i]) sum_s[s[i]]++;
else sum_l[s[i]+1]++;
}
for (int i = 0; i < B; i++) {
sum_l[i+1] += sum_s[i];
sum_s[i+1] += sum_l[i+1];
}
auto induce = [&](V<int> &lms){
fill(begin(sa), end(sa), -1);
auto buf0 = sum_s;
for (auto d: lms) {
sa[buf0[s[d]]++] = d;
}
auto buf1 = sum_l;
for (int i = 0; i <= n; i++) {
int v = sa[i];
if (v >= 1 && !ls[v-1]) {
sa[buf1[s[v-1]]++] = v-1;
}
}
auto buf2 = sum_l;
for (int i = n; i >= 0; i--) {
int v = sa[i];
if (v >= 1 && ls[v-1]) {
sa[--buf2[s[v-1]+1]] = v-1;
}
}
};
V<int> lms, lms_map(n+1, -1);
for (int i = 1; i <= n; i++) {
if (!ls[i-1] && ls[i]) {
lms_map[i] = int(lms.size());
lms.push_back(i);
}
}
induce(lms);
if (lms.size() >= 2) {
int m = int(lms.size())-1;
V<int> lms2;
for (int v: sa) {
if (lms_map[v] != -1) lms2.push_back(v);
}
int rec_n = 1;
V<int> rec_s(m);
rec_s[lms_map[lms2[1]]] = 1;
for (int i = 2; i <= m; i++) {
int l = lms2[i-1], r = lms2[i];
int nl = lms[lms_map[l]+1], nr = lms[lms_map[r]+1];
if (nl-l != nr-r) rec_n++;
else {
while (l <= nl) {
if (s[l] != s[r]) {
rec_n++;
break;
}
l++; r++;
}
}
rec_s[lms_map[lms2[i]]] = rec_n;
}
V<int> nx_lms;
auto ch_sa = sa_is(rec_s, rec_n);
for (int d: ch_sa) {
nx_lms.push_back(lms[d]);
}
induce(nx_lms);
}
return sa;
}
template<class Str>
V<int> doublingSA(Str s) {
int n = (int)s.size();
V<int> sa(n+1);
V<int> rsa(n+1);
iota(begin(sa), end(sa), 0);
for (int i = 0; i <= n; i++) {
rsa[i] = i < n ? s[i] : -1;
}
vector<int> tmp(n+1);
for (int k = 1; k <= n; k *= 2) {
auto cmp = [&](int x, int y){
if (rsa[x] != rsa[y]) return rsa[x] < rsa[y];
int rx = x+k <= n ? rsa[x+k] : -1;
int ry = y+k <= n ? rsa[y+k] : -1;
return rx < ry;
};
sort(begin(sa), end(sa), cmp);
tmp[sa[0]] = 0;
for (int i = 1; i <= n; i++) {
tmp[sa[i]] = tmp[sa[i-1]] + (cmp(sa[i-1], sa[i]) ? 1 : 0);
}
copy(begin(tmp), end(tmp), begin(rsa));
}
return sa;
}