void ILCPConstruct(const SuffixArray& sa,
std::vector<SuffixArray::Index>* ilcp) {
typedef SuffixArray::Index Index;
std::vector<Index>& text_lcp = *ilcp;
text_lcp.resize(sa.size());
Index start = 0;
int num_docs = 0;
const char* text = sa.text();
for (Index i = 0; i <= (Index)sa.size(); ++i) {
if (i == (Index)sa.size() || (unsigned char)text[i] <= 1) {
const char* doc = text + start;
Index doc_len = i - start;
SuffixArray doc_sa(doc, doc_len);
for (Index j = 0; j < doc_len; ++j) {
Index p = doc_sa.sa(j);
Index lcp = doc_sa.lcp(j);
text_lcp[start + p] = lcp;
}
num_docs++;
start = i;
}
}
std::vector<bool> visited(sa.size());
// permutate text_lcp[i] = text_lcp[sa[i]] implace
for (Index i = 0; i < (Index)sa.size(); ++i) {
if (!visited[i]) {
int j = i;
while (true) {
visited[j] = 1;
Index to = sa.sa(j);
if (visited[to]) break;
std::swap(text_lcp[j], text_lcp[to]);
j = to;
}
}
// ilcp[i] = text_lcp[sa.sa(i)];
}
}
std::vector<int> longest_common_prefix(const T &s, const SuffixArray &sa){
const int n = sa.size();
std::vector<int> vs(n), isa(n), lcp(n - 1);
for(int i = 0; i + 1 < n; ++i){ vs[i] = s[i]; }
for(int i = 0; i < n; ++i){ isa[sa[i]] = i; }
int h = 0;
for(int i = 0; i < n; ++i){
const int j = isa[i];
if(j > 0){
const int k = j - 1;
while(vs[sa[j] + h] == vs[sa[k] + h]){ ++h; }
lcp[k] = h;
if(h > 0){ --h; }
}
}
return lcp;
}
