后缀数组 hihocoder 1084 Extend KMP

注意到k <= 5

#include <iostream>#include <queue> #include <stack> #include <map> #include <set> #include <bitset> #include <cstdio> #include <algorithm> #include <cstring> #include <climits>#include <cstdlib>#include <cmath>#include <time.h>#define maxn 200005#define maxm 2000005#define eps 1e-10#define mod 1000000007#define INF 0x3f3f3f3f#define PI (acos(-1.0))#define lowbit(x) (x&(-x))#define mp make_pair#define ls o<<1#define rs o<<1 | 1#define lson o<<1, L, mid #define rson o<<1 | 1, mid+1, R#define pii pair<int, int>//#pragma comment(linker, "/STACK:16777216")typedef long long LL;typedef unsigned long long ULL;//typedef int LL;using namespace std;LL qpow(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base;base=base*base;b/=2;}return res;}LL powmod(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base%mod;base=base*base%mod;b/=2;}return res;}// headchar s[maxn];  int sa[maxn], c[maxn], t1[maxn], t2[maxn];  int rank[maxn], height[maxn];  void build(int n, int m)  {      int *x = t1, *y = t2, p;      for(int i = 0; i < m; i++) c[i] = 0;      for(int i = 0; i < n; i++) c[x[i] = s[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 k = 1; k <= n; k <<= 1) {          p = 0;          for(int i = n-k; i < n; i++) y[p++] = i;          for(int i = 0; i < n; i++) if(sa[i] >= k) y[p++] = sa[i] - k;          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];          p = 1, swap(x, y), x[sa[0]] = 0;          for(int i = 1; i < n; i++)              x[sa[i]] = y[sa[i]] == y[sa[i-1]] && y[sa[i] + k] == y[sa[i-1] + k] ? p-1 : p++;          if(p >= n) break;          m = p;      }  }  void getheight(int n)  {      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 j = sa[rank[i] - 1];          while(s[i + k] == s[j + k]) k++;          height[rank[i]] = k;      }  }    int p[maxn];  int st1[maxn][20];  int sum[maxn];  void init(int n, int *a, int (*t)[20])  {      p[0] = -1;      for(int i = 1; i <= n; i++) p[i] = i & (i-1) ? p[i-1] : p[i-1] + 1;      for(int i = 1; i <= n; i++) t[i][0] = a[i];      for(int j = 1; j <= p[n]; j++)          for(int i = 1; i + (1 << j) - 1 <= n; i++)              t[i][j] = min(t[i][j-1], t[i + (1 << (j-1))][j-1]);  }  int query(int l, int r, int (*t)[20])  {      int k = p[r - l + 1];      return min(t[l][k], t[r - (1 << k) + 1][k]);  }  int lcp(int a, int b)  {      if(a > b) swap(a, b);      return query(a+1, b, st1);  }  char pp[maxn];int k;void read(void){scanf("%s", pp);scanf("%d", &k);}void work(void){int len = strlen(s);int t = strlen(pp);s[len] = 'A';for(int i = len+1; i <= len + t; i++) s[i] = pp[i - len - 1];int n = len;s[len + t + 1] = '\0';len = len + t + 1;build(len + 1, 128);getheight(len);init(len, height, st1);int ans = 0;//for(int i = 0; i < len; i++) printf("AA %d \n", lcp(rank[0], rank[8]));int tmp;for(int i = 0; i <= n - t; i++) {int j = n + 1, cnt = 0, now = i;tmp = 0;while(cnt <= k) {tmp = lcp(rank[now], rank[j]);now += tmp;j += tmp;if(j - n - 1 >= t) {ans++;break;}now++, j++;cnt++;}//if(tmp && cnt == k+1) ans++;//if(cnt <= k) ans++;}printf("%d\n", ans);}int main(void){while(scanf("%s", s)!=EOF) {read();work();}return 0;}