贴出来，需要的时候查看和修改。其实基础是trie树，需要理解go和link函数。
1 #include<bits/stdc++.h> 2 #define pb push_back 3 #define FOR(i, n) for (int i = 0; i < (int)n; ++i) 4 #define dbg(x) cout << #x << " at line " << __LINE__ << " is: " << x << endl 5 typedef long long ll; 6 using namespace std; 7 typedef pair<int, int> pii; 8 const int maxn = 3e6 + 10; 9 const int M = 2e5 + 123; 10 struct node { 11 int term; 12 int nxt[26]; 13 int link; 14 int p, ps; 15 node() { 16 ps = p = -1; 17 term = -1; 18 fill(nxt, nxt + 26, -1); 19 link = -1; 20 } 21 }; 22 int ptr = 1; 23 node trie[maxn]; 24 25 int get_id(const string &s) { 26 int cur = 0; 27 for (char cc : s) { 28 int c = cc - 'a'; 29 if(trie[cur].nxt[c] == -1) { 30 assert(0); 31 } 32 cur = trie[cur].nxt[c]; 33 } 34 return trie[cur].term; 35 } 36 37 void add(const string &s, int id) { 38 int cur = 0; 39 for (char cc : s) { 40 int c = cc - 'a'; 41 if(trie[cur].nxt[c] == -1) { 42 trie[cur].nxt[c] = ptr++; 43 trie[ptr - 1].p = cur; 44 trie[ptr - 1].ps = c; 45 } 46 cur = trie[cur].nxt[c]; 47 } 48 trie[cur].term = id; 49 } 50 int link(int v); 51 int go(int v, int c) { 52 if(trie[v].nxt[c] != -1) { 53 return trie[v].nxt[c]; 54 } 55 if(v == 0) return 0; 56 return trie[v].nxt[c] = go(link(v), c); 57 } 58 int link(int v) { 59 if(trie[v].link != -1) return trie[v].link; 60 if(v == 0 || trie[v].p == 0) { 61 return 0; 62 } 63 return trie[v].link = go(link(trie[v].p), trie[v].ps); 64 } 65 int n, k; 66 set<int> q[M]; 67 void solve() { 68 cin >> n >> k; 69 string s; 70 cin >> s; 71 int l = s.size(); 72 s = s + s; 73 int g; 74 cin >> g; 75 for (int i = 0; i < g; i++) { 76 string t; 77 cin >> t; 78 add(t, i + 1); 79 } 80 int cur = 0; 81 for (int i = 0; i < 2 * l; i++) { 82 cur = go(cur, s[i] - 'a'); 83 if(trie[cur].term != -1) { 84 int beg = i - k + 1; 85 if(beg < l) { 86 q[beg % k].insert(cur); 87 } 88 } 89 } 90 for (int i = 0; i < k; i++) { 91 if(q[i].size() == n) { 92 cout << "YES" << endl; 93 for (int j = 0; j < n; j++) { 94 cout << get_id(s.substr(i + j * k, k)) << " "; 95 } 96 cout << endl; 97 return; 98 } 99 } 100 cout << "NO" << endl; 101 } 102 int main() { 103 freopen("test.in", "r", stdin); 104 //freopen("test.out", "w", stdout); 105 solve(); 106 return 0; 107 }
普通的写法，bfs建立失败节点，应该好理解一些！
1 #include<bits/stdc++.h> 2 #define pb push_back 3 #define FOR(i, n) for (int i = 0; i < (int)n; ++i) 4 #define dbg(x) cout << #x << " at line " << __LINE__ << " is: " << x << endl 5 typedef long long ll; 6 using namespace std; 7 typedef pair<int, int> pii; 8 const int maxn = 1e6 + 10; 9 int fail[maxn]; 10 int cnt = 0; 11 int pos[maxn]; 12 struct node { 13 int nxt[26]; 14 int type; 15 int l; 16 node() { 17 memset(nxt, -1, sizeof nxt); 18 type = l = 0; 19 } 20 } a[maxn]; 21 void add(string s) { 22 int cur = 0; 23 for (int i = 0; i < s.size(); i++) { 24 int id = s[i] - 'a'; 25 if(a[cur].nxt[id] == -1) { 26 a[cur].nxt[id] = ++cnt; 27 //cout << cnt << endl; 28 } 29 cur = a[cur].nxt[id]; 30 } 31 a[cur].type = 1; 32 a[cur].l = s.size(); 33 } 34 void bt() { 35 queue<int> q; 36 fail[0] = 0; 37 for (int i = 0; i < 26; i++) { 38 if(a[0].nxt[i] == -1) { 39 a[0].nxt[i] = 0; 40 } else { 41 fail[a[0].nxt[i] ] = 0; 42 q.push(a[0].nxt[i]); 43 } 44 } 45 while(!q.empty()) { 46 int now = q.front(); 47 q.pop(); 48 for (int i = 0; i < 26; i++) { 49 if(a[now].nxt[i] == -1) { 50 a[now].nxt[i] = a[fail[now] ].nxt[i]; 51 } else { 52 fail[a[now].nxt[i] ] = a[fail[now] ].nxt[i]; 53 q.push(a[now].nxt[i]); 54 } 55 } 56 } 57 } 58 void work(string s) { 59 memset(pos, 0, sizeof pos); 60 int now = 0; 61 for (int i = 0; i < s.size(); i++) { 62 int id = s[i] - 'a'; 63 now = a[now].nxt[id]; 64 int tmp = now; 65 while(tmp != 0) { 66 if(a[tmp].type == 1) { 67 pos[i + 1] -= 1; 68 pos[i - a[tmp].l + 1 ] += 1; 69 //cout << i << endl; 70 break; 71 } 72 tmp = fail[tmp]; 73 } 74 } 75 int cnt = 0; 76 for (int i = 0; i < s.size(); i++) { 77 cnt += pos[i]; 78 if(cnt <= 0) cout << s[i]; 79 else cout << "*"; 80 } 81 cout << endl; 82 } 83 void solve() { 84 int n; 85 cin >> n; 86 string s; 87 for (int i = 1; i <= n; i++) { 88 cin >> s; 89 //cout << s << endl; 90 add(s); 91 } 92 bt(); 93 cin >> s; 94 work(s); 95 } 96 int main() { 97 freopen("test.in", "r", stdin); 98 //freopen("test.out", "w", stdout); 99 ios::sync_with_stdio(0); 100 cin.tie(0); cout.tie(0); 101 solve(); 102 return 0; 103 }