HUNAN 11569 Just Another Knapsack Problem(AC自动机+dp)

http://acm.hunnu.edu.cn/online/?action=problem&type=show&id=11569&courseid=0

给出目标串,每个子串和对应的权值,然后要从子串中匹配出目标串并且权值最大.匹配的位置不能重复.

dp[i]为匹配到i这个位置时的最大价值,那么dp[i]=max(dp[i],dp[i-len[j]]+val[j]);

每次找到的匹配的子串在目标串的位置,然后动态转移。

 #include <iostream>
 #include <cstdio>
 #include <cmath>
 #include <vector>
 #include <cstring>
 #include <algorithm>
 #include <string>
 #include <set>
 #include <functional>
 #include <numeric>
 #include <sstream>
 #include <stack>
 #include <map>
 #include <queue>

 #define CL(arr, val)    memset(arr, val, sizeof(arr))

 #define ll long long
 #define inf 0x7f7f7f7f
 #define lc l,m,rt<<1
 #define rc m + 1,r,rt<<1|1
 #define pi acos(-1.0)

 #define L(x)    (x) << 1
 #define R(x)    (x) << 1 | 1
 #define MID(l, r)   (l + r) >> 1
 #define Min(x, y)   (x) < (y) ? (x) : (y)
 #define Max(x, y)   (x) < (y) ? (y) : (x)
 #define E(x)        (1 << (x))
 #define iabs(x)     (x) < 0 ? -(x) : (x)
 #define OUT(x)  printf("%I64d\n", x)
 #define lowbit(x)   (x)&(-x)
 #define Read()  freopen("a.txt", "r", stdin)
 #define Write() freopen("dout.txt", "w", stdout);

 #define Nn 510007
 #define Mc 26

 using namespace std;

 class Acautomaton
 {
     private:

     int chd[Nn][Mc];
     int fail[Nn];
     int ID[Mc];
     int val[Nn];
     int Q[Nn];
     int sz;
     int len[Nn];

     public:
     int dp[];
     void Init()
     {
         fail[] = ;
         for (int i = ; i < Mc; ++i)
         {
             ID[i] = i;
         }
     }
     void Reset()
     {
         CL(chd[],);
         sz = ;
     }
     int idx(char c) {return c-'a';}
     void insert(char *s,int key)
     {
         int p = ;
         for (; *s; s++)
         {
             int k = ID[*s - 'a'];
             if (!chd[p][k])
             {
                 CL(chd[sz],);
                 val[sz] = ;
                 len[sz]=;
                 chd[p][k] = sz++;
             }
             len[chd[p][k]]=len[p]+;
             p = chd[p][k];
         }
         val[p] =max(val[p], key);
     }
     void Build()
     {
         int *s = Q ,*e = Q,i;
         for (i = ; i < Mc; ++i)
         {
             if (chd[][i])
             {
                 *e++ = chd[][i];
                 fail[chd[][i]] = ;
             }
         }
         while (s != e)
         {
             int u = *s++;
             for (i = ; i < Mc; ++i)
             {
                 int &v = chd[u][i];
                 if (v)
                 {
                     *e++ = v;
                     fail[v] = chd[fail[u]][i];
                 }
                 else v = chd[fail[u]][i];
             }
         }
     }
     void find(char *T) {
         int j=;
         for(int i=,temp,c;T[i];i++) {
             dp[i]=;
             c=idx(T[i]);
             while(j&&!chd[j][c]) j=fail[j];
             j=chd[j][c];
             temp=j;
             while(temp) {
                 if(val[temp]) {
                     //printf("%d\n",val[temp]);
                     if(i-len[temp]<) //temp已经在目标串中出现,但是不能转移
                         dp[i]=max(dp[i],val[temp]);
                     else if(dp[i-len[temp]])
                         dp[i]=max(dp[i],dp[i-len[temp]]+val[temp]);
                     printf("%d %d %d\n",i,dp[i],len[temp]);
                 }
                 temp=fail[temp];
             }

         }
     }
    /* int solve(char *s)
     {
         int p = 0;
         int k,ans = 0;
         for (; *s; s++)
         {
             k = ID[*s - 'a'];
             while (!chd[p][k] && p != 0) p = fail[p];

             p = chd[p][k];

             int rt = p;
             while (rt != 0 && val[rt] != -1)
             {
                 ans += val[rt];
                 val[rt] = -1;
                 rt = fail[rt];
             }
         }
         return ans;
     }*/
 }ac;

 char s[],t[];

 int main()
 {
     Read();
     int n,val,i;
     while (~scanf("%s",s))
     {
         ac.Reset(); ac.Init();
         scanf("%d",&n);
         for (i = ; i < n; ++i){
             scanf("%s %d",t,&val);
             ac.insert(t,val);
         }
         ac.Build();
         ac.find(s);
         //scanf("%s",tr);
         printf("%d\n",ac.dp[strlen(s)-]);
     }
     return ;
 }