学步园

AC自动机+状态压缩DP， 由于时限卡的比较死，进制高低位的选择不同可能会导致TLE（o(╯□╰)o），详细见注释

#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>

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::istringstream;
using std::make_pair;
using std::getline;
using std::greater;
using std::endl;
using std::multimap;

typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int, int> PAIR;
typedef multimap<int, int> MMAP;

const int MAXN(510);
const int SIGMA_SIZE(4);
const int MAXM(110);
const int MAXE(4000010);
const int MAXH(18);
const int INFI((INT_MAX-1) >> 2);
const int MOD(20090717);
const ULL LIM(1000000000000000ull);

int mp[128];

struct AC
{
    int ch[MAXN][SIGMA_SIZE];
    int val[MAXN], f[MAXN];
    int size;
    
    void init()
    {
        memset(ch[0], 0, sizeof(ch[0]));
        f[0] = val[0] = 0;
        size = 1;
    }
    
    inline int idx(char temp)
    {
        return mp[temp];        
    }
    
    void insert(char *S)
    {
        int u = 0, id;
        for(; *S; ++S)
        {
            id = idx(*S);
            if(!ch[u][id])
            {
                memset(ch[size], 0, sizeof(ch[size]));
                val[size] = 0;
                ch[u][id] = size++;
            }
            u = ch[u][id];
        }
        val[u] += 1;  
    }
    
    int que[MAXN];
    int front, back;
    void construct()
    {
        front = back = 0;
        int cur, u;
        for(int i = 0; i < SIGMA_SIZE; ++i)
        {
            u = ch[0][i];
            if(u)
            {
                que[back++] = u;
                f[u] = 0;
            }
        }
        while(front < back)
        {
            cur = que[front++];
            for(int i = 0; i < SIGMA_SIZE; ++i)
            {
                u = ch[cur][i];
                if(u)
                {
                    que[back++] = u;
                    f[u] = ch[f[cur]][i];
                    val[u] += val[f[u]];
                }
                else
                    ch[cur][i] = ch[f[cur]][i];
            }
        }
    }
};

AC ac;

int BASE[4];
int quant[4];

inline int encode()
{
    return quant[0]*BASE[0]+quant[1]*BASE[1]+quant[2]*BASE[2]+quant[3]*BASE[3];
}

bool vis[MAXN][15010];
int table[MAXN][15010];
int code;     

//注意每个状态编码可以通过减法递推得到，不要重新计算
int dfs(int u)
{
    if(vis[u][code])
        return table[u][code];
    int &cur = table[u][code];
    cur = 0;
    int ts, temp;
    for(int i = 0; i < SIGMA_SIZE; ++i)
        if(quant[i])
        {
            --quant[i];
            code -= BASE[i];
            ts = ac.ch[u][i];
            temp = dfs(ts)+ac.val[ts];
            cur = temp > cur? temp: cur;
            code += BASE[i];
            ++quant[i];
        }
    vis[u][code] = true;
    return cur;
}

void solve()
{
    memset(vis, 0, sizeof(vis[0])*ac.size);
    code = encode();
    dfs(0);
    printf("%d\n", table[0][code]);
}
char str[60];

int main()
{
    mp['A'] = 0;
    mp['C'] = 1;
    mp['G'] = 2;
    mp['T'] = 3;
    int n, n_case(0);
    while(scanf("%d", &n), n)
    {    
        ac.init();
        for(int i = 0; i < n; ++i)
        {
            scanf("%s", str);
            ac.insert(str);
        }
        ac.construct();
        scanf("%s", str);
        quant[0] = quant[1] = quant[2] = quant[3] = 0;
        for(char *pi = str; *pi; ++pi)
            ++quant[mp[*pi]];
        BASE[3] = 1;         //如果把'A'作为低位的话就会TLE，还要注意注意每个位的的状态数为quant+1
        BASE[2] = quant[3]+1;
        BASE[1] = (quant[2]+1)*BASE[2];
        BASE[0] = (quant[1]+1)*BASE[1];
        printf("Case %d: ", ++n_case);
        solve();
    }
    return 0;
}