题意:给定两个串A,B,问你A有多少不同的子串,并且不包含B。
析:首先A有多少个不同的子串,可以用后缀数组来解决,也就是 n - sa[i] - h[i] + 1。但是要是不包含B,可以先预处理A和B,把B在A中的位置都记录下来,然后在找不同子串的时候,走到匹配的位置就停止,如果再向后找就肯定包含B了。
代码如下:
#pragma comment(linker, "/STACK:1024000000,1024000000") #include <cstdio> #include <string> #include <cstdlib> #include <cmath> #include <iostream> #include <cstring> #include <set> #include <queue> #include <algorithm> #include <vector> #include <map> #include <cctype> #include <cmath> #include <stack> #include <sstream> #include <list> #include <assert.h> #include <bitset> #define debug() puts("++++"); #define gcd(a, b) __gcd(a, b) #define lson l,m,rt<<1 #define rson m+1,r,rt<<1|1 #define fi first #define se second #define pb push_back #define sqr(x) ((x)*(x)) #define ms(a,b) memset(a, b, sizeof a) #define sz size() #define pu push_up #define pd push_down #define cl clear() //#define all 1,n,1 #define FOR(i,x,n) for(int i = (x); i < (n); ++i) #define freopenr freopen("in.txt", "r", stdin) #define freopenw freopen("out.txt", "w", stdout) using namespace std; typedef long long LL; typedef unsigned long long ULL; typedef pair<int, int> P; const int INF = 0x3f3f3f3f; const double inf = 1e20; const double PI = acos(-1.0); const double eps = 1e-8; const int maxn = 5e4 + 20; const int maxm = 100 + 10; const ULL mod = 10007; const int dr[] = {-1, 0, 1, 0}; const int dc[] = {0, -1, 0, 1}; const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"}; int n, m; const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; inline bool is_in(int r, int c) { return r >= 0 && r < n && c >= 0 && c < m; } struct Suffix_array{ int s[maxn], sa[maxn], t[maxn]; int t2[maxn], h[maxn], r[maxn], c[maxn]; int n; void init(){ n = 0; ms(sa, 0); } void build_sa(int m){ int *x = t, *y = t2; 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){ int 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]; swap(x, y); p = 1; x[sa[0]] = 0; for(int i = 1; i < n; ++i) x[sa[i]] = y[sa[i]] == y[sa[i-1]] && y[sa[i-1]+k] == y[sa[i]+k] ? p-1 : p++; if(p >= n) break; m = p; } } void getHight(){ int k = 0; for(int i = 0; i < n; ++i) r[sa[i]] = i; for(int i = 0; i < n; ++i){ if(k) --k; int j = sa[r[i]-1]; while(s[i+k] == s[j+k]) ++k; h[r[i]] = k; } } }; Suffix_array arr; char s[maxn], t[maxn]; int f[maxn]; void getFail(){ f[0] = f[1] = 0; for(int i = 1; i < m; ++i){ int j = f[i]; while(j && s[i] != s[j]) j = f[j]; f[i+1] = s[i] == s[j] ? j + 1 : 0; } } vector<int> v; int main(){ int T; cin >> T; for(int kase = 1; kase <= T; ++kase){ scanf("%s", t); scanf("%s", s); arr.init(); v.cl; m = strlen(s); getFail(); int j = 0; for(int i = 0; t[i]; ++i){ arr.s[arr.n++] = t[i] - 'a' + 1; while(j && s[j] != t[i]) j = f[j]; if(s[j] == t[i]) ++j; if(j == m) v.pb(i), j = f[j]; } arr.s[arr.n++] = 0; v.pb(INF); arr.build_sa(28); arr.getHight(); int ans = 0; j = 0; for(int i = 0; i < arr.n; ++i){ int x = *lower_bound(v.begin(), v.end(), arr.sa[i] + m - 1); ++x; ans += max(0, min(x, arr.n) - arr.sa[i] - arr.h[i] - 1); } printf("Case %d: %d\n", kase, ans); } return 0; }