[HDOJ2457]DNA repair

Trie图（AC自动机）+DP~

#include <cstdio>
  2 #include <cstring>
  3 
  4 #define MIN(a,b) (a < b ? a : b)
  5 
  6 usingnamespace std;
  7 
  8 constint NS =4;
  9 constint MAXL =32;
 10 constint SIZE =1024;
 11 constchar* DNA ="ACGT";
 12 
 13 int node;
 14 bool danger[SIZE];
 15 int suffix[SIZE];
 16 int next[SIZE][NS];
 17 int queue[SIZE];
 18 
 19 int dp[SIZE][SIZE];
 20 
 21 char description[SIZE];
 22 
 23 inline int getIndex(char c)
 24 {
 25 return strchr(DNA,c) - DNA;
 26 }
 27 
 28 int TrieInit()
 29 {
 30     node =0;
 31     danger[0] =false;
 32     suffix[0] =-1;
 33     memset(next[0],-1,sizeof(next[0]));
 34 return node++;
 35 }
 36 
 37 void TrieInsert(char* word,int root)
 38 {
 39 char* key;
 40 int tmp;
 41 
 42     key = word;
 43     tmp = root;
 44 
 45 while (*key)
 46     {
 47 int idx = getIndex(*key++);
 48 if (next[tmp][idx] ==-1)
 49         {
 50             danger[node] =false;
 51             suffix[node] =-1;
 52             memset(next[node],-1,sizeof(next[node]));
 53             next[tmp][idx] = node++;
 54         }
 55         tmp = next[tmp][idx];
 56     }
 57     danger[tmp] =true;
 58 }
 59 
 60 void getSuffix(int root)
 61 {
 62 int qh =-1;
 63 int qe =0;
 64 
 65     queue[0] = root;
 66 
 67 while (qh != qe)
 68     {
 69         qh++;
 70 int tmp = queue[qh];
 71 for (int i =0;i < NS;i++)
 72 if (next[tmp][i] !=-1)
 73             {
 74 int now = next[tmp][i];
 75 int p = suffix[tmp];
 76 while (p !=-1&& next[p][i] ==-1) p = suffix[p];
 77 if (p ==-1) suffix[now] = root;
 78 else
 79                 {
 80                     suffix[now] = next[p][i];
 81                     danger[now] = danger[now] || danger[next[p][i]];
 82                 }
 83                 queue[++qe] = now;
 84             }
 85 else
 86             {
 87 int p = suffix[tmp];
 88 while (p !=-1&& next[p][i] ==-1) p = suffix[p];
 89 if (p ==-1) next[tmp][i] = root;
 90 else next[tmp][i] = next[p][i];
 91             }
 92     }
 93 }
 94 
 95 int main ()
 96 {
 97 int n;
 98 char word[MAXL];
 99 
100 for(int cc =1;scanf("%d",&n) ==1&& n;cc++)
101     {
102 int root = TrieInit();
103 for (int i =0;i < n;i++)
104         {
105             scanf("%s",word);
106             TrieInsert(word,root);
107         }
108 
109         getSuffix(root);
110 
111         scanf("%s",description);
112 
113 int len = strlen(description);
114 
115 for (int i =0;i <= len;i++)
116 for (int j =0;j < node;j++)
117                 dp[i][j] = SIZE;
118         dp[0][0] =0;
119 
120 for (int i =1;i <= len;i++)
121 for (int j =0;j < node;j++)
122 if (!danger[j])
123 for (int k =0;k < NS;k++)
124 if (!danger[next[j][k]])
125                             dp[i][next[j][k]] = MIN(dp[i][next[j][k]],dp[i-1][j] + (getIndex(description[i-1]) == k ?0 : 1));
126 int ans = SIZE;
127 for (int i =0;i < node;i++)
128 if (!danger[i] && ans > dp[len][i])
129                 ans = dp[len][i];
130 
131         printf("Case %d: %d\n",cc,ans == SIZE ?-1 : ans);
132     }
133 return0;
134 }