1 #include <iostream> 2 #include <cstdio> 3 #include <cstring> 4 #include <cstdlib> 5 #include <algorithm> 6 #include <queue> 7 #include <vector> 8 #include <stack> 9 #include <map> 10 #include <set> 11 #include <cmath> 12 #include <cctype> 13 #include <ctime> 14 #include <ext/rope> 15 16 using namespace std; 17 using namespace __gnu_cxx; 18 19 #define REP(i, n) for (int i = 0; i < (n); ++i) 20 #define eps 1e-9 21 #define SZ(x) ((int)x.size()) 22 23 typedef long long ll; 24 typedef pair<int, int> pii; 25 26 #define PI acos(-1.0) 27 const int maxn = 1e5 + 10; 28 struct Complex { 29 double x, y; 30 Complex(double _x = 0.0, double _y = 0.0) { x = _x; y = _y; } 31 Complex operator - (const Complex &b) const { return Complex(x - b.x, y - b.y); } 32 Complex operator + (const Complex &b) const { return Complex(x + b.x, y + b.y); } 33 Complex operator * (const Complex &b) const { return Complex(x * b.x - y * b.y, x * b.y + y * b.x); } 34 }; 35 char str_A[maxn], str_B[maxn]; 36 Complex A[maxn * 4], B[maxn * 4], ans[maxn * 4]; 37 int ans_final[maxn * 4], len_final = 0; 38 int N, M, n = 1; 39 40 void fft(Complex a[], int len, int oper) { 41 for (int i = 1, j = 0; i < len - 1; ++i) { 42 for (int s = len; ~j & s;) { j ^= s >>= 1; } 43 if (i < j) { swap(a[i], a[j]); } 44 } 45 Complex omega_m, omega, t, u; 46 int m, m2; 47 for (int d = 0; (1 << d) < len; ++d) { 48 m = (1 << d); m2 = m << 1; 49 omega_m = Complex(cos(PI / m * oper), sin(PI / m * oper)); 50 for (int i = 0; i < len; i += m2) { 51 omega = Complex(1, 0); 52 for (int j = 0; j < m; ++j) { 53 u = a[i + j]; t = omega * a[i + j + m]; 54 a[i + j] = u + t; a[i + j + m] = u - t; 55 omega = omega * omega_m; 56 } 57 } 58 } 59 if (oper == -1) { REP(i, N + M - 1) { a[i].x /= len; } } 60 } 61 62 63 int main() { 64 #ifdef __AiR_H 65 freopen("in.txt", "r", stdin); 66 // freopen("out.txt", "w", stdout); 67 #endif // __AiR_H 68 while (scanf("%s %s", str_A, str_B) != EOF) { 69 memset(ans, 0, sizeof(ans)); memset(ans_final, 0, sizeof(ans_final)); 70 N = strlen(str_A); M = strlen(str_B); n = 1; 71 while (n < N + M - 1) { n <<= 1; } 72 REP(i, N) { A[i] = Complex(str_A[N - 1 - i] - '0', 0); } 73 for (int i = N; i < n; ++i) { A[i] = Complex(0, 0); } 74 REP(i, M) { B[i] = Complex(str_B[M - 1 - i] - '0', 0); } 75 for (int i = M; i < n; ++i) { B[i] = Complex(0, 0); } 76 fft(A, n, 1); fft(B, n, 1); 77 REP(i, n) { ans[i] = A[i] * B[i]; } 78 fft(ans, n, -1); 79 REP(i, N + M) { ans_final[i] = ans[i].x + 0.5; } 80 REP(i, N + M - 1) { ans_final[i + 1] += ans_final[i] / 10; ans_final[i] %= 10; } 81 len_final = N + M - 1; 82 if (ans_final[len_final]) { ++len_final; } 83 while (ans_final[len_final - 1] == 0 && len_final > 1) { --len_final; } 84 for (int i = len_final - 1; i > 0; --i) { printf("%d", ans_final[i]); } printf("%d\n", ans_final[0]); 85 } 86 return 0; 87 }
1 #include <iostream> 2 #include <cstdio> 3 #include <cstring> 4 #include <cstdlib> 5 #include <algorithm> 6 #include <queue> 7 #include <vector> 8 #include <stack> 9 #include <map> 10 #include <set> 11 #include <cmath> 12 #include <cctype> 13 #include <ctime> 14 #include <ext/rope> 15 16 using namespace std; 17 using namespace __gnu_cxx; 18 19 #define REP(i, n) for (int i = 0; i < (n); ++i) 20 #define eps 1e-9 21 #define SZ(x) ((int)x.size()) 22 23 typedef long long ll; 24 typedef pair<int, int> pii; 25 26 #define PI acos(-1.0) 27 const int maxn = 1e5 + 10; 28 struct Complex { 29 double x, y; 30 Complex(double _x = 0.0, double _y = 0.0) { x = _x; y = _y; } 31 Complex operator - (const Complex &b) const { return Complex(x - b.x, y - b.y); } 32 Complex operator + (const Complex &b) const { return Complex(x + b.x, y + b.y); } 33 Complex operator * (const Complex &b) const { return Complex(x * b.x - y * b.y, x * b.y + y * b.x); } 34 }; 35 int T, n_t, N, M, n; 36 Complex A[maxn * 4], B[maxn * 4], mul[maxn * 4]; 37 int a[maxn]; 38 ll ans[maxn * 4], sum[maxn * 4]; 39 40 void fft(Complex a[], int len, int oper) { 41 for (int i = 1, j = 0; i < len - 1; ++i) { 42 for (int s = len; ~j & s;) { j ^= s >>= 1; } 43 if (i < j) { swap(a[i], a[j]); } 44 } 45 Complex omega_m, omega, t, u; 46 int m, m2; 47 for (int d = 0; (1 << d) < len; ++d) { 48 m = (1 << d); m2 = m << 1; 49 omega_m = Complex(cos(PI / m * oper), sin(PI / m * oper)); 50 for (int i = 0; i < len; i += m2) { 51 omega = Complex(1, 0); 52 for (int j = 0; j < m; ++j) { 53 u = a[i + j]; t = omega * a[i + j + m]; 54 a[i + j] = u + t; a[i + j + m] = u - t; 55 omega = omega * omega_m; 56 } 57 } 58 } 59 if (oper == -1) { REP(i, N + M - 1) { a[i].x /= len; } } 60 } 61 void init() { 62 memset(A, 0 ,sizeof(A)); memset(B, 0, sizeof(B)); 63 memset(mul, 0, sizeof(mul)); memset(ans, 0, sizeof(ans)); n = 1; 64 } 65 66 int main() { 67 #ifdef __AiR_H 68 freopen("in.txt", "r", stdin); 69 // freopen("out.txt", "w", stdout); 70 #endif // __AiR_H 71 scanf("%d", &T); 72 while (T--) { 73 scanf("%d", &n_t); init(); 74 for (int i = 1; i <= n_t; ++i) { 75 scanf("%d", &a[i]); ++A[a[i]].x; ++B[a[i]].x; 76 } 77 sort(a + 1, a + n_t + 1); N = M = a[n_t] + 1; 78 while (n < N + M - 1) { n <<= 1; } 79 fft(A, n, 1); fft(B, n, 1); 80 for (int i = 0; i < n; ++i) { mul[i] = A[i] * B[i]; } fft(mul, n, -1); 81 for (int i = 1; i < N + M; ++i) { ans[i] = (ll)(mul[i].x + 0.5); } 82 for (int i = 1; i <= n_t; ++i) { --ans[a[i] + a[i]]; } 83 for (int i = 1; i <= N + M; ++i) { ans[i] /= 2; } 84 for (int i = 1; i <= N + M; ++i) { sum[i] = sum[i - 1] + ans[i]; } 85 ll ans1 = 1ll * n_t * (n_t - 1) * (n_t - 2) / 6, ans2 = 0; 86 for (int i = 1; i <= n_t; ++i) { 87 ans2 += sum[N + M] - sum[a[i]]; 88 ans2 -= 1ll * (i - 1) * (n_t - i); 89 ans2 -= n_t - 1; 90 ans2 -= 1ll * (n_t - i) * (n_t - i - 1) / 2; 91 } 92 printf("%.7f\n", 1.0 * ans2 / ans1); 93 } 94 return 0; 95 }
1 UVALive 4671 K-neighbor substrings
1 #include <iostream> 2 #include <cstdio> 3 #include <cstring> 4 #include <cstdlib> 5 #include <algorithm> 6 #include <queue> 7 #include <vector> 8 #include <stack> 9 #include <map> 10 #include <set> 11 #include <cmath> 12 #include <cctype> 13 #include <ctime> 14 #include <ext/rope> 15 16 using namespace std; 17 using namespace __gnu_cxx; 18 19 #define REP(i, n) for (int i = 0; i < (n); ++i) 20 #define eps 1e-9 21 #define SZ(x) ((int)x.size()) 22 #define PI acos(-1.0) 23 24 typedef long long ll; 25 typedef unsigned long long ull; 26 typedef pair<int, int> pii; 27 const int maxn = 1e5 + 10; 28 struct Complex { 29 double x, y; 30 Complex(double _x = 0.0, double _y = 0.0) { x = _x; y = _y; } 31 Complex operator - (const Complex &b) const { return Complex(x - b.x, y - b.y); } 32 Complex operator + (const Complex &b) const { return Complex(x + b.x, y + b.y); } 33 Complex operator * (const Complex &b) const { return Complex(x * b.x - y * b.y, x * b.y + y * b.x); } 34 }; 35 ull Hash[maxn], Pow[maxn]; 36 set<ull> s; 37 int k, len1, len2, Case = 0, N, M, n; 38 char s1[maxn], s2[maxn]; 39 Complex A[maxn * 4], B[maxn * 4], mul[maxn * 4]; 40 int ans1[maxn * 4], ans2[maxn * 4]; 41 42 void fft(Complex a[], int len, int oper) { 43 for (int i = 1, j = 0; i < len - 1; ++i) { 44 for (int s = len; ~j & s;) { j ^= s >>= 1; } 45 if (i < j) { swap(a[i], a[j]); } 46 } 47 Complex omega_m, omega, t, u; 48 int m, m2; 49 for (int d = 0; (1 << d) < len; ++d) { 50 m = (1 << d); m2 = m << 1; 51 omega_m = Complex(cos(PI / m * oper), sin(PI / m * oper)); 52 for (int i = 0; i < len; i += m2) { 53 omega = Complex(1, 0); 54 for (int j = 0; j < m; ++j) { 55 u = a[i + j]; t = omega * a[i + j + m]; 56 a[i + j] = u + t; a[i + j + m] = u - t; 57 omega = omega * omega_m; 58 } 59 } 60 } 61 if (oper == -1) { REP(i, N + M - 1) { a[i].x /= len; } } 62 } 63 int solve(int ans[], char c) { 64 memset(A, 0, sizeof(A)); memset(B, 0, sizeof(B)); 65 for (int i = 0; i < len1; ++i) { 66 if (s1[i] == c) { A[i].x = 1; } 67 } 68 for (int i = 0; i < len2; ++i) { 69 if (s2[i] == c) { B[i].x = 1; } 70 } 71 fft(A, n, 1); fft(B, n, 1); 72 for (int i = 0; i < n; ++i) { mul[i] = A[i] * B[i]; } 73 fft(mul, n, -1); 74 for (int i = len2 - 1; i < N + M; ++i) { ans[i] = mul[i].x + 0.5; } 75 } 76 77 int main() { 78 #ifdef __AiR_H 79 freopen("in.txt", "r", stdin); 80 // freopen("out.txt", "w", stdout); 81 #endif // __AiR_H 82 Pow[0] = 1; ull t; Hash[0] = 0; 83 for (int i = 1; i < maxn; ++i) { Pow[i] = Pow[i - 1] * 131; } 84 while (scanf("%d", &k) && k != -1) { 85 scanf("%s %s", s1, s2); len1 = strlen(s1); len2 = strlen(s2); 86 if (len1 < len2) { printf("Case %d: 0\n", ++Case); continue; } 87 reverse(s2, s2 + len2); s.clear(); 88 N = len1; M = len2; n = 1; while (n < N + M - 1) { n <<= 1; } 89 solve(ans1, 'a'); solve(ans2, 'b'); 90 for (int i = 0; i < len1; ++i) { Hash[i + 1] = Hash[i] * 131 + s1[i]; } 91 for (int i = 0; i <= len1 - len2; ++i) { 92 t = Hash[i + len2] - Hash[i] * Pow[len2]; 93 if (len2 - ans1[i + len2 - 1] - ans2[i + len2 - 1] <= k) { 94 s.insert(t); 95 } 96 } 97 printf("Case %d: %d\n", ++Case, (int)s.size()); 98 } 99 return 0; 100 }
