字符串
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//普通 void getnext1(char *s) { int i = 0,j = -1,len = strlen(s); ne[0] = -1; while(i < len) { if(j == -1 || s[i] == s[j]) ne[++i] = ++j; else j = ne[j]; } } //加快预处理 void getnext2(char *s) { int i = 0,j = -1,len = strlen(s); ne[0] = -1; while(i < len) { if(j == -1 || s[i] == s[j]) { if(s[++i] == s[++j]) ne[i] = ne[j]; else ne[i] = j; } else j = ne[j]; } } //反悔x在y中出现的次数，可以重叠 int kmp(char *x,char *y) { getnext1(x); int i = 0,j = 0,ans = 0,leny = strlen(y),lenx = strlen(x); while(i < leny) { if(j == -1 || x[j] == y[i]) { i++,j++; if(j == lenx) { ans++; j = ne[j]; } } else j = ne[j]; } return ans; }
//求浮动匹配 //l[i]表示i结点之前(包括i结点),小于a[i]的个数 //le[i]表示i结点之前(包括i结点),小于等于a[i]的个数 //l[i] == l[j] && le[i] == le[j],则匹配 #include<bits/stdc++.h> using namespace std; int n,k,s,a[100005],b[25005],ne[25005],tree[30],l[100005],le[100005]; inline int lowbit(int x) { return x&-x; } void update(int pos,int x) { while(pos <= s) { tree[pos] += x; pos += lowbit(pos); } } int getsum(int pos) { int sum = 0; while(pos) { sum += tree[pos]; pos -= lowbit(pos); } return sum; } void getnext1() { memset(tree,0,sizeof(tree)); int i = 0,j = -1; ne[0] = -1; while(i < k) { if(j == -1 || getsum(b[i]-1) == l[j] && getsum(b[i]) == le[j]) { ne[++i] = ++j; if(i < k) update(b[i],1); } else { for(int t = i-j;t < i-ne[j];t++) update(b[t],-1); j = ne[j]; } } } vector<int> kmp() { getnext1(); memset(tree,0,sizeof(tree)); vector<int> ans; int i = 0,j = 0; update(a[0],1); while(i < n) { if(j == -1 || getsum(a[i]-1) == l[j] && getsum(a[i]) == le[j]) { i++,j++; if(i < n) update(a[i],1); if(j == k) { ans.push_back(i-k+1); for(int t = i-j;t < i-ne[j];t++) update(a[t],-1); j = ne[j]; } } else { for(int t = i-j;t < i-ne[j];t++) update(a[t],-1); j = ne[j]; } } return ans; } int main() { while(~scanf("%d%d%d",&n,&k,&s)) { memset(tree,0,sizeof(tree)); memset(l,0,sizeof(l)); memset(le,0,sizeof(le)); memset(ne,0,sizeof(ne)); for(int i = 0;i < n;i++) scanf("%d",&a[i]); for(int i = 0;i < k;i++) { scanf("%d",&b[i]); update(b[i],1); l[i] = getsum(b[i]-1); le[i] = getsum(b[i]); } vector<int> v = kmp(); printf("%d\n",v.size()); for(int i = 0;i < v.size();i++) printf("%d\n",v[i]); } return 0; }
void getnext(char *s) { int j = 0,len = strlen(s),k = 1; ne[0] = len; while(j+1 < len && s[j] == s[j+1]) j++; ne[1] = j; for(int i = 2;i < len;i++) { if(ne[i-k]+i < ne[k]+k) ne[i] = ne[i-k]; else { j = max(0,ne[k]+k-i); while(i+j < len && s[i+j] == s[j]) j++; ne[i] = j; k = i; } } } void ekmp(char *x,char *y) { getnext(x); int j = 0,lenx = strlen(x),leny = strlen(y); while(j < lenx && j < leny && x[j] == y[j]) j++; ex[0] = j; int k = 0; for(int i = 1;i < leny;i++) { if(ne[i-k]+i < ex[k]+k) ex[i] = ne[i-k]; else { j = max(0,ex[k]+k-i); while(i+j < leny && j < lenx && y[i+j] == x[j]) j++; ex[i] = j; k = i; } } }
//abaa //i: 0 1 3 4 5 6 7 8 9 10 //a[i]: $ # a # b # a # a # //p[i]: 1 1 2 1 4 1 2 3 2 1 #include<bits/stdc++.h> using namespace std; char s[100005],a[200005]; int p[200005]; void manacher(int len) { int mx = 0,id; for(int i = 1;i < len;i++) { if(mx > i) p[i] = min(p[2*id-i],mx-i); else p[i] = 1; while(a[i+p[i]] == a[i-p[i]]) p[i]++; if(p[i]+i > mx) { mx = p[i]+i; id = i; } } } int main() { scanf("%s",s); a[0] = ‘$‘; a[1] = ‘#‘; int len = 2; for(int i = 0;s[i];i++) { a[len++] = s[i]; a[len++] = ‘#‘; } manacher(len); int ans = 0; for(int i = 0;i < len;i++) ans = max(ans,p[i]); printf("%d\n",ans-1); return 0; }
//添加 void add(char *s,int x) { int now = 0; for(int i = 0;i < strlen(s);i++) { int c = s[i]-‘a‘; if(!ch[now][c]) { ch[now][c] = ++sz; cnt[sz] = 0; } now = ch[now][c]; cnt[now]++; } } //查找数量 int getnum(char *s) { int now = 0; for(int i = 0;i < strlen(s);i++) { int c = s[i]-‘a‘; if(!ch[now][c]) return 0; now = ch[now][c]; } return cnt[now]; }
//HDU2222 //求目标中出现了几个模式串 #include<bits/stdc++.h> using namespace std; struct Trie { int next[500000][26],fail[500005],num[500005],root,cnt; int newnode() { for(int i = 0;i < 26;i++) next[cnt][i] = -1; num[cnt++] = 0; return cnt-1; } void init() { cnt = 0; root = newnode(); } void insert(char *s) { int now = root,len = strlen(s); for(int i = 0;i < len;i++) { int c = s[i]-‘a‘; if(next[now][c] == -1) next[now][c] = newnode(); now = next[now][c]; } num[now]++; } void build() { queue<int> q; fail[root] = root; for(int i = 0;i < 26;i++) { if(next[root][i] == -1) next[root][i] = root; else { fail[next[root][i]] = root; q.push(next[root][i]); } } while(!q.empty()) { int now = q.front(); q.pop(); for(int i = 0;i < 26;i++) { if(next[now][i] == -1) next[now][i] = next[fail[now]][i]; else { fail[next[now][i]] = next[fail[now]][i]; q.push(next[now][i]); } } } } int query(char *s) { int now = root,ans = 0,len = strlen(s); for(int i = 0;i < len;i++) { now = next[now][s[i]-‘a‘]; int t = now; while(t != root) { ans += num[t]; num[t] = 0; t = fail[t]; } } return ans; } void debug() { for(int i = 0;i < cnt;i++) { printf("id = %3d,fail = %3d,num = %3d,chi = [",i,fail[i],num[i]); for(int j = 0;j < 26;j++) printf("%2d",next[i][j]); printf("]\n"); } } }; int n; char s[1000001]; Trie ac; int main() { int T; scanf("%d",&T); while(T--) { scanf("%d",&n); ac.init(); while(n--) { scanf("%s",s); ac.insert(s); } ac.build(); scanf("%s",s); printf("%d\n",ac.query(s)); } return 0; }
//O(nlogn) /待排序数组长度n,放在0~n中，最后补0 //sa[i]:每个后缀串从小到大排第i小的位置 //rank[i]:i位置的从小到大排序位置 //height[i]:sa[i]和sa[i-1]对应后缀的最长公共前缀 //n = 8 //num[i]: 1 1 2 1 1 1 1 2 0 num[8]加0 //sa[i]: 8 3 4 5 0 6 1 7 2 num[0~n]有效 //rank[i]: 4 6 8 1 2 3 5 7 0 num[0~n-1]有效 //height[i]:0 0 3 2 3 1 2 0 1 num[2~n]有效 int t1[N],t2[N],c[N],sa[N],rank[N],height[N]; int mm[200005],best[20][200005],rmq[200005]; int main() { gets(s); int len = strlen(s); for(int i = 0;i < len;i++) r[i] = s[i]; da(r,sa,rk,height,len,128); return 0; } bool cmp(int *r,int a,int b,int l) { return r[a] == r[b] && r[a+l] == r[b+l]; } void da(int *r,int *sa,int *rank,int *height,int n,int m) { r[n] = 0; n++; int *x = t1,*y = t2; for(int i = 0;i < m;i++) c[i] = 0; for(int i = 0;i < n;i++) c[x[i] = r[i]]++; for(int i = 1;i < m;i++) c[i] += c[i-1]; for(int i = n-1;i >= 0;i--) sa[--c[x[i]]] = i; for(int j = 1;j <= n;j <<= 1) { int p = 0; for(int i = n-j;i < n;i++) y[p++] = i; for(int i = 0;i < n;i++) { if(sa[i] >= j) y[p++] = sa[i]-j; } for(int i = 0;i < m;i++) c[i] = 0; for(int i = 0;i < n;i++) c[x[y[i]]]++; for(int i = 1;i < m;i++) c[i] += c[i-1]; for(int i = n-1;i >= 0;i--) sa[--c[x[y[i]]]] = y[i]; swap(x,y); p = 1; x[sa[0]] = 0; for(int i = 1;i < n;i++) x[sa[i]] = cmp(y,sa[i-1],sa[i],j)?p-1:p++; if(p >= n) break; m = p; } int k = 0; n--; for(int i = 0;i <= n;i++) rank[sa[i]] = i; for(int i = 0;i < n;i++) { if(k) k--; int t = sa[rank[i]-1]; while(r[i+k] == r[t+k]) k++; height[rank[i]] = k; } } void initrmq(int n) { mm[0] = -1; for(int i = 1;i < n;i++) mm[i] = (i&(i-1) == 0)?mm[i-1]+1:mm[i-1]; for(int i = 1;i < n;i++) best[0][i] = i; for(int i = 1;i <= mm[n-1];i++) { for(int j = 1;j+(1<<i)-1 < n;j++) { int a = best[i-1][j],b = best[i-1][j+(1<<(i-1))]; best[i][j] = rmq[a] < rmq[b]?a:b; } } } int askrmq(int a,int b) { int t = mm[b-a+1]; b -= (1<<t)-1; a = best[t][a]; b = best[t][b]; return rmq[a] < rmq[b]?a:b; } //求a,b位置开始的后缀的最长公共前缀 int lcp(int a,int b) { a = rk[a]; b = rk[b]; if(a > b) swap(a,b); return height[askrmq(a+1,b)]; }
//O(n) //所有数组开3倍 #include<bits/stdc++.h> #define F(x) ((x)/3+((x)%3 == 1?0:tb)) #define G(x) ((x) < tb?(x)*3+1:((x)-tb)*3+2) #define N 2005 using namespace std; int wa[3*N],wb[3*N],wv[3*N],wss[3*N],r[3*N],sa[3*N],rk[3*N],height[3*N]; char s[3*N]; int c0(int *r,int a,int b) { return r[a] == r[b] && r[a+1] == r[b+1] && r[a+2] == r[b+2]; } int c12(int k,int *r,int a,int b) { if(k == 2) return r[a] < r[b] || r[a] == r[b] && c12(1,r,a+1,b+1); return r[a] < r[b] || r[a] == r[b] && wv[a+1] < wv[b+1]; } void sort(int *r,int *a,int *b,int n,int m) { for(int i = 0;i < n;i++) wv[i] = r[a[i]]; for(int i = 0;i < m;i++) wss[i] = 0; for(int i = 0;i < n;i++) wss[wv[i]]++; for(int i = 1;i < m;i++) wss[i] += wss[i-1]; for(int i = n-1;i >= 0;i--) b[--wss[wv[i]]] = a[i]; } void dc3(int *r,int *sa,int n,int m) { int *rn = r+n,*san = sa+n,ta = 0,tb = (n+1)/3,tbc = 0,i,j,p; r[n]=r[n+1]=0; for(i = 0;i < n;i++) { if(i%3) wa[tbc++] = i; } sort(r+2,wa,wb,tbc,m); sort(r+1,wb,wa,tbc,m); sort(r,wa,wb,tbc,m); for(p = 1,rn[F(wb[0])] = 0,i = 1;i < tbc;i++) { rn[F(wb[i])] = c0(r,wb[i-1],wb[i])?p-1:p++; } if(p < tbc) dc3(rn,san,tbc,p); else { for(i = 0;i < tbc;i++) san[rn[i]] = i; } for(i = 0;i < tbc;i++) { if(san[i] < tb) wb[ta++] = san[i]*3; } if(n%3 == 1) wb[ta++] = n-1; sort(r,wb,wa,ta,m); for(i = 0;i < tbc;i++) wv[wb[i] = G(san[i])]=i; for(i = 0,j = 0,p = 0;i < ta && j < tbc;p++) sa[p] = c12(wb[j]%3,r,wa[i],wb[j])?wa[i++]:wb[j++]; for(;i < ta;p++) sa[p] = wa[i++]; for(;j < tbc;p++) sa[p] = wb[j++]; } void da(int *r,int *sa,int *rank,int *height,int n,int m) { for(int i = n;i < n*3;i++) r[i] = 0; dc3(r,sa,n+1,m); int k = 0; for(int i = 0;i <= n;i++) rank[sa[i]] = i; for(int i = 0;i < n;i++) { if(k) k--; int t = sa[rank[i]-1]; while(r[i+k] == r[t+k]) k++; height[rank[i]] = k; } }
struct samnode { samnode *fa,*next[26]; int len; void clear() { fa = NULL; len = 0; memset(next,0,sizeof(next)); } }; samnode *root,*last,st[2*N]; int sz; char s[10005]; int topcnt[2*N]; samnode *topsam[2*N]; void saminit() { sz = 0; root = last = &st[sz++]; root ->clear(); } void samadd(int w) { samnode *p = last,*np = &st[sz++]; last = np; np->clear(); np->len = p->len+1; while(p && !p->next[w]) { p->next[w] = np; p = p->fa; } if(!p) { np->fa = root; return; } samnode *q = p->next[w]; if(q->len == p->len+1) { np->fa = q; return; } samnode *nq = &st[sz++]; nq->clear(); nq->len = p->len+1; memcpy(nq->next,q->next,sizeof(q->next)); nq->fa = q->fa; q->fa = nq; np->fa = nq; while(p && p->next[w] == q) { p->next[w] = nq; p = p->fa; } } void sambuild(char *s) { saminit(); int len = strlen(s); for(int i = 0;i < len;i++) samadd(s[i]-‘a‘); } int main() { gets(s); sambuild(s); memset(topcnt,0,sizeof(topcnt)); for(int i = 0;i < sz;i++) topcnt[st[i].len]++; for(int i = 1;i <= strlen(s);i++) topcnt[i] += topcnt[i-1]; for(int i = 0;i < sz;i++) topsam[--topcnt[st[i].len]] = &st[i]; return 0; }
#include<bits/stdc++.h> using namespace std; const int HASH = 10007; const int N = 2010; const int SEED = 13331; char s[N]; struct HASHMAP { int head[N],next[N],size,f[N]; unsigned long long state[N]; void init() { size = 0; memset(state,-1,sizeof(state)); } int insert(unsigned long long x,int id) { int h = x%HASH; for(int i = head[h];i != -1;i = next[i]) { if(x == state[i]) return f[i]; } f[size] = id; state[size] = x; next[size] = head[h]; head[h] = size++; return 0; } }; int main() { gets(s); int len = strlen(s); unsigned long long t = 0; for(int i = 1;i <= len;i++) t = t*SEED+s[i-1]; }
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