http://codeforces.com/contest/316/problem/G3
SAM上DP
在某岛的博客上看到的,要义就是一个串的子串必然是该串某个后缀的前缀,所以从表示该状态的子串节点往后走必然会走到那个串的尾节点。
#include <iostream> #include <cstdio> #include <cstdlib> #include <cmath> #include <queue> #include <algorithm> #include <vector> #include <cstring> #include <stack> #include <cctype> #include <utility> #include <map> #include <string> #include <climits> #include <set> #include <string> #include <sstream> #include <utility> #include <ctime> #include <bitset> #include <iomanip> //#pragma comment(linker, "/STACK:102400000,102400000") using std::priority_queue; using std::vector; using std::swap; using std::stack; using std::sort; using std::max; using std::min; using std::pair; using std::map; using std::string; using std::cin; using std::cout; using std::set; using std::queue; using std::string; using std::stringstream; using std::make_pair; using std::getline; using std::greater; using std::endl; using std::multimap; using std::deque; using std::unique; using std::lower_bound; using std::random_shuffle; using std::bitset; using std::upper_bound; using std::multiset; using std::ios; using std::make_heap; using std::push_heap; using std::pop_heap; typedef long long LL; typedef unsigned long long ULL; typedef unsigned UN; typedef pair<ULL, ULL> PAIR; typedef multimap<int, int> MMAP; typedef long double LF; const int MAXN(600100); const int MAXM(310); const int MAXE(310); const int MAXK(6); const int HSIZE(13131); const int SIGMA_SIZE(26+11); const int MAXH(18); const int INFI((INT_MAX-1) >> 1); const ULL BASE(31); const LL LIM(1e13); const int INV(-10000); const int MOD(1000000007); const double EPS(1e-7); const LF PI(acos(-1.0)); template<typename T> inline void checkmax(T &a, T b){if(b > a) a = b;} template<typename T> inline void checkmin(T &a, T b){if(b < a) a = b;} template<typename T> inline T ABS(const T &a){return a < 0? -a: a;} struct NODE { int len; NODE *ch[SIGMA_SIZE], *f; int dp[11]; }; struct SAM { NODE pool[MAXN << 1], *rear, *last; void init() { last = pool; last->len = 0; last->f = 0; memset(last->ch, 0, sizeof(last->ch)); rear = pool+1; } void extend(int id) { NODE *p = last, *np = rear++; np->len = last->len+1; memset(np->ch, 0, sizeof(np->ch)); last = np; while(p && !p->ch[id]) { p->ch[id] = np; p = p->f; } if(!p) np->f = pool; else { NODE *q = p->ch[id]; if(q->len == p->len+1) np->f = q; else { NODE *nq = rear++; nq->len = p->len+1; memcpy(nq->ch, q->ch, sizeof(nq->ch)); nq->f = q->f; q->f = np->f = nq; while(p && p->ch[id] == q) { p->ch[id] = nq; p = p->f; } } } } int buc[MAXN], size; NODE *rec[MAXN << 1]; void tupo() { size = rear-pool; memset(buc, 0, sizeof(buc[0])*(last->len+1)); for(NODE *p = pool; p < rear; ++p) ++buc[p->len]; for(int i = 1; i <= last->len; ++i) buc[i] += buc[i-1]; for(NODE *p = rear-1; p >= pool; --p) rec[--buc[p->len]] = p; } } sam; char str[50010]; int l[11], r[11]; int main() { scanf("%s", str); sam.init(); for(char *sp = str; *sp; ++sp) sam.extend(*sp-'a'); sam.extend(26); int n; scanf("%d", &n); for(int i = 1; i <= n; ++i) { scanf("%s%d%d", str, l+i, r+i); for(char *sp = str; *sp; ++sp) sam.extend(*sp-'a'); sam.extend(26+i); } sam.tupo(); int ans = 0; for(int i = sam.size-1; i > 0; --i) { NODE *p = sam.rec[i]; for(int i = 0; i <= n; ++i) if(p->ch[i+26]) p->dp[i] = 1; for(int i = 0; i < 26; ++i) if(p->ch[i]) { for(int j = 0; j <= n; ++j) p->dp[j] += p->ch[i]->dp[j]; } if(p->dp[0]) { bool flag(true); for(int i = 1; i <= n; ++i) if(p->dp[i] < l[i] || p->dp[i] > r[i]) { flag = false; break; } if(flag) ans += p->len-p->f->len; } } printf("%d\n", ans); return 0; }