HDU 2825 Wireless Password (AC automaton + state compression DP)

Title Link: Wireless Password

Parsing: A set of M words that counts the number of programs with at least K words in a string of all lengths of N.

AC Automaton + state compression DP.

DP[I][J][K]: String of length I matches to status J and contains the number of possible strings for K magic word.

AC Code:

#include <algorithm> #include <iostream> #include <cstdio> #include <queue> #include < cstring>using namespace Std;const int MOD = 20090717;int N, m, k;int dp[30][110][1<<10];int num[5000];struct Trie    {int next[110][26], fail[110], end[110];    int root, L;        int NewNode () {for (int i=0; i<26; i++) Next[l][i] =-1;        end[l++] = 0;    return L-1;        } void Init () {L = 0;    root = NewNode ();        } void Insert (char buf[], int id) {int len = strlen (BUF);        int now = root; for (int i=0; i<len; i++) {if (Next[now][buf[i]-' a '] = =-1) next[now][buf[i]-' a '] = NewNode            ();        now = next[now][buf[i]-' a '];             } End[now] |= (1<<id);        Note} void Build () {queue<int> Q;        Fail[root] = root;            for (int i=0; i<26; i++) {if (next[root][i] = =-1) next[root][i] = root;            else{    Fail[next[root][i]] = root;            Q.push (Next[root][i]); }} while (!            Q.empty ()) {int now = Q.front ();            Q.pop ();            End[now] |= End[fail[now];                for (int i=0; i<26; i++) {if (next[now][i] = =-1) next[now][i] = Next[fail[now]][i];                    else{Fail[next[now][i]] = next[fail[now]][i];                Q.push (Next[now][i]);          }}}} int solve () {//memset (DP, 0, sizeof (DP)); Memset initializes the DP array, which is slower than the following for (int i=0; i<=n; i++) for (int j=0; j<l; j + +) for (int p=0; p < (1&LT;&LT;M);        p++) Dp[i][j][p] = 0;        Dp[0][0][0] = 1;                    for (int i=0, i<n; i++) for (int j=0; j<l; j + +) for (int p=0; p< (1<<m); p++)             if (Dp[i][j][p] > 0) {for (int x=0; x<26; x + +) {               int newi = i+1;                            int newj = next[j][x];                            int newp = (p | end[newj]);                            DP[NEWI][NEWJ][NEWP] + = dp[i][j][p];                        DP[NEWI][NEWJ][NEWP]%= MOD;        }} int ans = 0;            for (int p=0; p< (1<<m); p++) {if (Num[p] < k) Continue;        for (int i=0; i<l; i++) ans = (ans + dp[n][i][p])% MOD;    } return ans; }};char BUF[20];    Trie Ac;int Main () {//Freopen ("In.txt", "R", stdin);        for (int i=0; i< (1<<10); i++) {num[i] = 0;    for (int j=0; j<10; J + +) if (I & (1&LT;&LT;J)) Num[i] + +;        } while (scanf ("%d%d%d", &n, &m, &k) = = 3) {if (n = = 0 && m = = 0 && k = = 0) break;        Ac.init ();            for (int i=0; i<m; i++) {scanf ("%s", buf);        Ac.insert (buf, i);    } ac.build ();    printf ("%d\n", Ac.solve ()); } return 0;}

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HDU 2825 Wireless Password (AC automaton + state compression DP)