模板

Trie

HIHOCODER1014

static final int N = (int)1e5+10;
static final int SIGMA=(int)27;
static int ch[][]=new int[N*10][SIGMA],sz;
static int var[]=new int[N*10];
static void insert(String x){int u=0;for(int i=0;i<x.length();i++){int c=x.charAt(i)-'a';if(ch[u][c]==0){for(int t=0;t<SIGMA;t++){ch[sz][t]=0;}ch[u][c]=sz;var[sz++]=0;}u=ch[u][c];var[u]++;}
}
static int search(String x){int u=0;for(int i=0;i<x.length();i++){int c=x.charAt(i)-'a';if(ch[u][c]!=0) u=ch[u][c];else return 0;}return var[u];
}
static void clear() {sz=1;var[0]=0;for(int i=0;i<SIGMA;i++) {ch[0][i]=0; }
}

KMP

HIHOCODER 1015

写法1

     static void getFail(char[] b) {int m=b.length,j=0;f[0]=f[1]=0;for(int i=1;i<m;i++) {while(j>0&&b[j]!=b[i]) j=f[j];if(b[j]==b[i]) j++;f[i+1]=j;}}static int kmp_count(char[] a,char[] b) {int n=a.length,m=b.length;int j=0,res=0;for(int i=0;i<n;i++) {while(j>0&&b[j]!=a[i]) j=f[j];if(b[j]==a[i]) j++;if(j==m) {j=0;res++;}}return res;}

写法2

    static void getFail(char[] b,int m) {int j=0;f[1]=0;for(int i=2;i<=m;i++) {while(j>0&&b[j+1]!=b[i]) j=f[j];if(b[j+1]==b[i]) j++;f[i]=j;}}static int kmp_count(char[] a,char[] b,int n,int m) {int j=0,res=0;for(int i=1;i<=n;i++) {while(j>0&&b[j+1]!=a[i]) j=f[j];if(b[j+1]==a[i]) j++;if(j==m) {j=0;res++;}}return res;}

Manacher

HIHOCODER1016

static final int N=(int)1e6+10;
static char a[]=new char[N],str[]=new char[2*N+5];
static int p[]=new int[2*N+5],len1,len2;
static void Init(){len1=a.length;str[0]='(';str[1]='#';for(int i=0;i<len1;i++){str[i*2+2]=a[i];str[i*2+3]='#';}len2=len1*2+2;str[len2]=')';
}
static int Manacher(){for(int i=0;i<len2;i++) p[i]=0;int id=0,mx=0,ans=0;for(int i=1;i<len2;i++){if(mx>i) p[i]=Math.min(mx-i,p[2*id-i]);else p[i]=1;for(;str[i+p[i]]==str[i-p[i]];p[i]++);if(p[i]+i>mx){mx=p[i]+i;id=i;}if(p[i]-1>ans) ans=p[i]-1;}return ans;
}

Tire图

HIHOCODER 1036

static int sz;
static final int N=1000005;
static class Node{Node(){post = 0;for(int i = 0; i < 26; i++)next[i] = 0;end = false;}int post;int next[]=new int[26];boolean end;
};static Node nodes[]=new Node[N];
//将str添加到trie图中
static void insert(String str){int cur=0;for(int i=0;i<str.length();i++){if(nodes[cur].next[str.charAt(i)-'a'] == 0)nodes[cur].next[str.charAt(i)-'a'] = ++sz;cur = nodes[cur].next[str.charAt(i)-'a'];}nodes[cur].end = true;
}
//为trie图中的每个点添加它指向的后缀点位置
static void addPost(){LinkedList<Integer> que = new LinkedList<Integer>();que.push(0);int cur;while(!que.isEmpty()){cur=que.pop();for(int i=0;i<26;i++){if(nodes[cur].next[i]!=0){que.push(nodes[cur].next[i]);if(cur != 0)//不是根结点，需要设置当前点的子节点的后缀=父结点的后缀经过i到达的点nodes[nodes[cur].next[i]].post = nodes[nodes[cur].post].next[i];}else //nodes[current].next[i] == -1当前点经过i没有可达的nodes[cur].next[i] = nodes[nodes[cur].post].next[i];}}
}//查找str
static boolean search(String str){int cur = 0;for(int i=0;i<str.length();i++){if(nodes[nodes[cur].next[str.charAt(i)-'a']].end)return true;cur = nodes[cur].next[str.charAt(i)-'a'];}return false;
}
static void Init() {sz=0;for(int i=0;i<=1000000;i++) {nodes[i]=new Node();}
}