/** * Copyright (c) 2016 Sergey Makagonov * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. * */ #include #include #include const int oo = 1<<25; const int ALPHABET_SIZE = 256; const int MAXN = 5000; using namespace std; int root, last_added, pos, needSL, remainder, active_node, active_e, active_len; struct node { /* There is no need to create an "Edge" struct. Information about the edge is stored right in the node. [start; end) interval specifies the edge, by which the node is connected to its parent node. */ int start, end, slink; int next[ALPHABET_SIZE]; int edge_length() { return min(end, pos + 1) - start; } }; node tree[2*MAXN]; char text[MAXN]; int new_node(int start, int end = oo) { node nd; nd.start = start; nd.end = end; nd.slink = 0; for (int i = 0; i < ALPHABET_SIZE; i++) nd.next[i] = 0; tree[++last_added] = nd; return last_added; } char active_edge() { return text[active_e]; } void add_SL(int node) { if (needSL > 0) tree[needSL].slink = node; needSL = node; } bool walk_down(int node) { if (active_len >= tree[node].edge_length()) { active_e += tree[node].edge_length(); active_len -= tree[node].edge_length(); active_node = node; return true; } return false; } void st_init() { needSL = 0, last_added = 0, pos = -1, remainder = 0, active_node = 0, active_e = 0, active_len = 0; root = active_node = new_node(-1, -1); } void st_extend(char c) { text[++pos] = c; needSL = 0; remainder++; while(remainder > 0) { if (active_len == 0) active_e = pos; if (tree[active_node].next[active_edge()] == 0) { int leaf = new_node(pos); tree[active_node].next[active_edge()] = leaf; add_SL(active_node); //rule 2 } else { int nxt = tree[active_node].next[active_edge()]; if (walk_down(nxt)) continue; //observation 2 if (text[tree[nxt].start + active_len] == c) { //observation 1 active_len++; add_SL(active_node); //observation 3 break; } int split = new_node(tree[nxt].start, tree[nxt].start + active_len); tree[active_node].next[active_edge()] = split; int leaf = new_node(pos); tree[split].next[c] = leaf; tree[nxt].start += active_len; tree[split].next[text[tree[nxt].start]] = nxt; add_SL(split); //rule 2 } remainder--; if (active_node == root && active_len > 0) { //rule 1 active_len--; active_e = pos - remainder + 1; } else active_node = tree[active_node].slink > 0 ? tree[active_node].slink : root; //rule 3 } } int main() { // return 0; }