diff options
Diffstat (limited to 'string/suffixArray.cpp')
| -rw-r--r-- | string/suffixArray.cpp | 38 |
1 files changed, 0 insertions, 38 deletions
diff --git a/string/suffixArray.cpp b/string/suffixArray.cpp deleted file mode 100644 index 8b698d2..0000000 --- a/string/suffixArray.cpp +++ /dev/null @@ -1,38 +0,0 @@ -constexpr int MAX_CHAR = 256; -struct SuffixArray { - int n; - vector<int> SA, LCP; - vector<vector<int>> P; - - SuffixArray(const string& s) : n(sz(s)), SA(n), LCP(n), - P(__lg(2 * n - 1) + 1, vector<int>(n)) { - P[0].assign(all(s)); - iota(all(SA), 0); - sort(all(SA), [&](int a, int b) {return s[a] < s[b];}); - vector<int> x(n); - for (int k = 1, c = 1; c < n; k++, c *= 2) { - iota(all(x), n - c); - for (int ptr = c; int i : SA) if (i >= c) x[ptr++] = i - c; - - vector<int> cnt(k == 1 ? MAX_CHAR : n); - for (int i : P[k-1]) cnt[i]++; - partial_sum(all(cnt), begin(cnt)); - for (int i : x | views::reverse) SA[--cnt[P[k-1][i]]] = i; - - auto p = [&](int i) {return i < n ? P[k-1][i] : -1;}; - for (int i = 1; i < n; i++) { - int a = SA[i-1], b = SA[i]; - P[k][b] = P[k][a] + (p(a) != p(b) || p(a+c) != p(b+c)); - }} - for (int i = 1; i < n; i++) LCP[i] = lcp(SA[i-1], SA[i]); - } - - int lcp(int x, int y) {//x & y are text-indices, not SA-indices - if (x == y) return n - x; - int res = 0; - for (int i = sz(P) - 1; i >= 0 && max(x, y) + res < n; i--) { - if (P[i][x + res] == P[i][y + res]) res |= 1 << i; - } - return res; - } -}; |
