Suffix Collections

Fast realization of suffix array and suffix tree for substring search, longest common prefix array (lcp array).

Example

• SuffixTree ```rust use suff_collections::{array::, tree::, lcp::*};

  // let word = "Some word"; let word: &str = "Some word\0"; let find: &str = "word";

  // construct suffix tree let st: SuffixTree = SuffixTree::new(word);

  // finds the entry position of the line 'find' in 'word' let res: Option = st.find(find);

  // construct lcp // lcp[i] = maxpref(sa[i], sa[i - 1]) && lcp.len() == sa.len() // let lcp: LCP = st.lcpstack::(); // let lcp: LCP = st.lcpstack::(); // let lcp: LCP = st.lcpstack::(); // let lcp: LCP = st.lcpstack::(); let lcp: LCP = st.lcprec::();

  // convert suffix tree to suffix array // let sa = SuffixArray::::fromstack(st); // let sa = SuffixArray::::fromstack(st); // let sa = SuffixArray::::fromstack(st); // let sa = SuffixArray::::fromstack(st); let sa = SuffixArray::::from_rec(st); ```

• SuffixArray ```rust use suff_collections::{array::, tree::, lcp::*};

  // let word = "Some word"; let word: &str = "Some word\0"; let find: &str = "word";

  // construct suffix array // let sa = SuffixArray::::new_stack(word); // let sa = SuffixArray::::new(word); // let sa = SuffixArray::::new(word); // let sa = SuffixArray::::new(word); let sa = SuffixArray::::new(word);

  // construct lcp // lcp[i] = max_pref(sa[i], sa[i - 1]) && lcp.len() == sa.len() let lcp: LCP = sa.lcp();

  // finds the entry position of the line 'find' in 'word' // O(|find| * log(|word|)) let res: Option = sa.find(find);

  // finds all the entry position of the line 'find' in 'word' // O(|find| * log(|word|)) let resall: &[usize] = sa.findall(find);

  // finds the entry position of the line 'find' in 'word' // O(|word|) let res: Option = sa.find_big(&sa.lcp(), find);

  // finds all the entry position of the line 'find' in 'word' // O(|word|) let resall: &[usize] = sa.findall_big(&sa.lcp(), find);

  // convert suffix array to suffix tree let st = SuffixTree::from(sa); ``` All construction and search work for O(n). For the suffix tree implementation the Ukkonen algorithm is taken and for the suffix array implementation the SA-IS algorithm is taken.

Some benches (thank Criterion)

• sufix_array\.lcp()

  time:   [401.96 us 403.67 us 405.75 us]
  

• sufix_array\.lcp()

  time:   [371.61 us 373.21 us 375.08 us]
  

• SuffixArray::\::new(LINE)

  time:   [2.2718 ms 2.2871 ms 2.3069 ms]
  

• SuffixArray::\::new(LINE)

  time:   [2.0291 ms 2.0368 ms 2.0456 ms]
  

• SuffixArray::\::new_stack(LINE)

  time:   [2.3389 ms 2.3777 ms 2.4314 ms]
  

• SuffixArray::\::new_stack(LINE)

  time:   [2.0221 ms 2.0310 ms 2.0405 ms]
  

• suffix_array\.find(FIND) ~ O(|find| * log(|word|))

  time:   [4.1127 us 4.1273 us 4.1415 us]
  

• suffix_array\.find(FIND) ~ O(|find| * log(|word|))

  time:   [4.1591 us 4.1695 us 4.1808 us]
  

• suffix_array\.find_all(FIND) ~ O(|find| * log(|word|))

  time:   [4.1205 us 4.1366 us 4.1528 us]
  

• suffix_array\.find_all(FIND) ~ O(|find| * log(|word|))

  time:   [4.1452 us 4.1560 us 4.1678 us]
  

• suffix_array\.find_big(FIND) ~ O(|word|)

  time:   [22.410 us 22.507 us 22.607 us]
  

• suffix_array\.find_big(FIND) ~ O(|word|)

  time:   [19.944 us 20.299 us 20.752 us]
  

• suffix_array\.find_big_all(FIND) ~ O(|word|)

  time:   [22.613 us 22.715 us 22.820 us]
  

• suffix_array\.find_big_all(FIND) ~ O(|word|)

  time:   [19.946 us 20.283 us 20.672 us]
  

• SuffixTree::from(suffix_array)

  time:   [13.533 ms 13.666 ms 13.812 ms]
  

• Suffix tree build Ukkonen

  time:   [15.316 ms 15.433 ms 15.558 ms]
  

• Suffix tree find

  time:   [20.506 us 20.839 us 21.221 us]
  

• SuffixArray::\::from_rec(suffix_tree)

  time:   [16.392 ms 16.494 ms 16.602 ms]
  

• SuffixArray::\::from_rec(suffix_tree)

  time:   [16.310 ms 16.411 ms 16.516 ms]
  

• SuffixArray::\::from_stack(suffix_tree)

  time:   [16.084 ms 16.210 ms 16.348 ms]
  

• SuffixArray::\::from_stack(suffix_tree)

  time:   [16.150 ms 16.260 ms 16.374 ms]
  

• suffix_tree.lcp_rec::\()

  time:   [6.7994 ms 6.8324 ms 6.8688 ms]
  

• suffix_tree.lcp_rec::\()

  time:   [6.5991 ms 6.6267 ms 6.6577 ms]
  

• suffix_tree.lcp_stack::\()

  time:   [6.2382 ms 6.2643 ms 6.2934 ms]
  

• suffix_tree.lcp_stack::\()

  time:   [6.2558 ms 6.2853 ms 6.3185 ms]