HDU-4749 Parade Show KMP算法 | DP

时间:2023-01-07 10:59:14

  题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4749

  题意:给两个串S和P,求S串中存在多少个与P串的大小关系一样的串。

  因为数字的范围是1<=k<=25之间,所以可以暴力的求25*25次KMP。当然完全没有必要这样做,在KMP的时候记录各个数的所表示的数就可以了,只需要求一遍KMP,复杂度降为O(25*n)。

  1 //STATUS:C++_AC_125MS_1596KB
  2 #include <functional>
  3 #include <algorithm>
  4 #include <iostream>
  5 //#include <ext/rope>
  6 #include <fstream>
  7 #include <sstream>
  8 #include <iomanip>
  9 #include <numeric>
 10 #include <cstring>
 11 #include <cassert>
 12 #include <cstdio>
 13 #include <string>
 14 #include <vector>
 15 #include <bitset>
 16 #include <queue>
 17 #include <stack>
 18 #include <cmath>
 19 #include <ctime>
 20 #include <list>
 21 #include <set>
 22 #include <map>
 23 using namespace std;
 24 #pragma comment(linker,"/STACK:102400000,102400000")
 25 //using namespace __gnu_cxx;
 26 //define
 27 #define pii pair<int,int>
 28 #define mem(a,b) memset(a,b,sizeof(a))
 29 #define lson l,mid,rt<<1
 30 #define rson mid+1,r,rt<<1|1
 31 #define PI acos(-1.0)
 32 //typedef
 33 typedef __int64 LL;
 34 typedef unsigned __int64 ULL;
 35 //const
 36 const int N=100010;
 37 const int INF=0x3f3f3f3f;
 38 const int MOD=9973,STA=8000010;
 39 const LL LNF=1LL<<60;
 40 const double EPS=1e-6;
 41 const double OO=1e60;
 42 const int dx[4]={-1,0,1,0};
 43 const int dy[4]={0,1,0,-1};
 44 const int day[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
 45 //Daily Use ...
 46 inline int sign(double x){return (x>EPS)-(x<-EPS);}
 47 template<class T> T gcd(T a,T b){return b?gcd(b,a%b):a;}
 48 template<class T> T lcm(T a,T b){return a/gcd(a,b)*b;}
 49 template<class T> inline T lcm(T a,T b,T d){return a/d*b;}
 50 template<class T> inline T Min(T a,T b){return a<b?a:b;}
 51 template<class T> inline T Max(T a,T b){return a>b?a:b;}
 52 template<class T> inline T Min(T a,T b,T c){return min(min(a, b),c);}
 53 template<class T> inline T Max(T a,T b,T c){return max(max(a, b),c);}
 54 template<class T> inline T Min(T a,T b,T c,T d){return min(min(a, b),min(c,d));}
 55 template<class T> inline T Max(T a,T b,T c,T d){return max(max(a, b),max(c,d));}
 56 //End
 57 
 58 int next[N],s[N],p[N],w[30],f[30];
 59 int T,n,m,k;
 60 
 61 void getnext(int *s,int len)
 62 {
 63     int j=0,k=-1;
 64     next[0]=-1;
 65     while(j<len){
 66         if(k==-1 || s[k]==s[j])
 67             next[++j]=++k;
 68         else k=next[k];
 69     }
 70 }
 71 
 72 int solve()
 73 {
 74     int i,j,ret=0,x,la=-1;
 75     for(i=j=0;i<n;i++){
 76         while(1){
 77             for(x=1;x<=k;x++){
 78                 if(f[x]>=j){w[x]=-1;continue;}
 79                 w[x]=p[i-j+f[x]];
 80             }
 81             if((j==-1||w[s[j]]==-1) || p[i]==w[s[j]])break;
 82             j=next[j];
 83         }
 84         j++;
 85         if(j==m && i>=la){la=i+m;ret++;}
 86     }
 87     return ret;
 88 }
 89 
 90 int main(){
 91  //   freopen("in.txt","r",stdin);
 92     int i,j,ans;
 93     while(~scanf("%d%d%d",&n,&m,&k))
 94     {
 95         for(i=0;i<n;i++){
 96             scanf("%d",&p[i]);
 97         }
 98         mem(f,-1);
 99         for(i=0;i<m;i++){
100             scanf("%d",&s[i]);
101             if(f[s[i]]==-1)f[s[i]]=i;
102         }
103         p[n]=0;s[m]=0;
104 
105         getnext(s,m);
106         ans=solve();
107 
108         printf("%d\n",ans);
109     }
110     return 0;
111 }