Codeforces Round #248 (Div. 1) C

C - Tachibana Kanade's Tofu

思路：把 n 个串丢进AC自动机中，然后dp就好啦。 我的代码居然是在CF上跑最快的。。

#include<bits/stdc++.h>
#define LL long long
#define fi first
#define se second
#define mk make_pair
#define PLL pair<LL, LL>
#define PLI pair<LL, int>
#define PII pair<int, int>
#define SZ(x) ((int)x.size())
#define ull unsigned long long

using namespace std;

const int N = 200 + 7;
const int inf = 0x3f3f3f3f;
const LL INF = 0x3f3f3f3f3f3f3f3f;
const int mod = 1e9 + 7;
const double eps = 1e-8;
const double PI = acos(-1);

int n, m, len, k, tmp, v[210];
vector<int> L, R;
vector<int> s;

inline void add(int &a, int b) {
    a += b; if(a >= mod) a -= mod;
}

struct Ac {
    int ch[202][20], val[202], f[202], tot, sz;
    int dp[2][202][502][2], cur, pre;
    void init(int _sz) {tot = 0; sz = _sz;}
    inline int newNode() {
        tot++; f[tot] = 0; val[tot] = 0;
        memset(ch[tot], 0, sizeof(ch[tot]));
        return tot;
    }
    inline int idx(int c) {return c;}
    void addStr(vector<int> &s, int cost) {
        int u = 0;
        for(int i = 0; i < s.size(); i++) {
            int c = idx(s[i]);
            if(!ch[u][c]) ch[u][c] = newNode();
            u = ch[u][c];
        }
        val[u] += cost;
    }
    void build() {
        queue<int> que;
        for(int c = 0; c < sz; c++) {
            int v = ch[0][c];
            if(!v) ch[0][c] = 0;
            else f[v] = 0, que.push(v);
        }
        while(!que.empty()) {
            int u = que.front(); que.pop();
            val[u] += val[f[u]];
            for(int c = 0; c < sz; c++) {
                int v = ch[u][c];
                if(!v) ch[u][c] = ch[f[u]][c];
                else f[v] = ch[f[u]][c], que.push(v);
            }
        }
    }
    int solve(vector<int> &str) {
        int n = str.size(), ans = 0;
        cur = 0, pre = 1;
        memset(dp[cur], 0, sizeof(dp[cur]));
        for(int z = 1; z <= str[0]; z++) {
            int v = ch[0][z];
            if(val[v] <= k) add(dp[cur][v][val[v]][z == str[0]], 1);
        }
        for(int i = 1; i < n; i++) {
            swap(cur, pre);
            memset(dp[cur], 0, sizeof(dp[cur]));
            for(int z = 1; z < m; z++) {
                int v = ch[0][z];
                if(val[v] <= k) add(dp[cur][v][val[v]][0], 1);
            }
            for(int u = 0; u <= tot; u++) {
                for(int s = 0; s <= k; s++) {
                    if(dp[pre][u][s][0]) {
                        for(int z = 0; z < m; z++) {
                            int v = ch[u][z];
                            if(s+val[v] <= k) add(dp[cur][v][val[v]+s][0], dp[pre][u][s][0]);
                        }
                    }

                    if(dp[pre][u][s][1]) {
                        for(int z = 0; z <= str[i]; z++) {
                            int v = ch[u][z];
                            if(s+val[v] <= k) add(dp[cur][v][val[v]+s][z==str[i]], dp[pre][u][s][1]);
                        }
                    }
                }
            }
        }
        for(int u = 0; u <= tot; u++)
            for(int j = 0; j <= k; j++)
        add(ans, dp[cur][u][j][0]), add(ans, dp[cur][u][j][1]);
        return ans;
    }
} ac;

int main() {
    scanf("%d%d%d", &n, &m, &k);
    ac.init(m);
    scanf("%d", &len); L.resize(len);
    for(int i = 0; i < len; i++) scanf("%d", &L[i]);
    scanf("%d", &len); R.resize(len);
    for(int i = 0; i < len; i++) scanf("%d", &R[i]);
    for(int i = 0; i < n; i++) {
        scanf("%d", &len); s.resize(len);
        for(int j = 0; j < len; j++) scanf("%d", &s[j]);
        int cost; scanf("%d", &cost);
        ac.addStr(s, cost);
        for(int p = 0; p+s.size() <= L.size(); p++) {
            bool flag = true;
            for(int q = 0; q < s.size(); q++) {
                if(s[q] != L[q+p]) {
                    flag = false;
                    break;
                }
            }
            if(flag) tmp += cost;
        }
    }
    ac.build();
    int ans = (ac.solve(R) - ac.solve(L) + (tmp <= k) + mod) % mod;
    printf("%d
", ans);
    return 0;
}
/*
*/