#include <bits/stdc++.h> #include <unistd.h> using namespace std; #define REP(i,n) for(int _n=(n), i=0;i<_n;++i) #define FOR(i,a,b) for(int i=(a),_b=(b);i<=_b;++i) #define FORD(i,a,b) for(int i=(a),_b=(b);i>=_b;--i) #define TRACE(x) cerr << "TRACE(" #x ")" << endl; #define DEBUG(x) cerr << #x << " = " << (x) << endl; typedef long long LL; typedef unsigned long long ULL; class Input { public: Input() { bufpos = bufend = buffer; eof = false; } bool Eof() { return eof; } char Peek() { if(bufpos == bufend) Grab(); return *bufpos; } unsigned char UPeek() { return static_cast<unsigned char>(Peek()); } void SkipWS(); template<class T> T Get(); void operator()() {} template<class Arg, class... Args> void operator()(Arg &arg, Args &... args) { arg = Get<Arg>(); operator()(args...); } private: static const int BUFSIZE = 1<<16; char buffer[BUFSIZE]; char *bufpos; char *bufend; bool eof; void Grab(); }; void Input::Grab() { if(eof) return; bufpos = buffer; bufend = buffer + read(0, buffer, BUFSIZE); if(bufend==bufpos) { eof=true; *bufpos=0; } } template<> inline char Input::Get<char>() { char res = Peek(); ++bufpos; return res; } void Input::SkipWS() { while(isspace(UPeek())) Get<char>(); } template<> unsigned Input::Get<unsigned>() { SkipWS(); unsigned x = 0; while(isdigit(UPeek())) { x = 10u * x + (Get<char>()-'0'); } return x; } template<> int Input::Get<int>() { SkipWS(); bool neg = false; if(Peek()=='-') { neg=true; Get<char>(); } unsigned x = Get<unsigned>(); if (neg) x = -x; return static_cast<int>(x); } Input IN; template<unsigned MOD> class Modulo { unsigned v; public: Modulo(unsigned x=0):v(x) {} unsigned get() const { return v; } Modulo operator+(Modulo b) const { unsigned res = v+b.v; if (res >= MOD) res -= MOD; return res; } void operator+=(Modulo b) { *this = *this + b; } Modulo operator-(Modulo b) const { return *this + Modulo(MOD-b.v); } void operator-=(Modulo b) { *this = *this - b; } Modulo operator*(Modulo b) const { return Modulo(ULL(v) * ULL(b.v) % MOD); } void operator*=(Modulo b) { *this = *this * b; } }; // [0..size1-1][base2 .. base2+size2-1] template <typename T> class Array2d { public: Array2d(int _size1, int _size2, int _base2) : size1(_size1), size2(_size2), base2(_base2), data(size1 * size2) {} T &operator()(int i, int j) { return data[i * size2 + j - base2]; } private: int size1; int size2; int base2; vector<T> data; }; using Mod = Modulo<1'000'000'007>; void read_input(int &a, int &b, int &c, int &d, int &r1, int &r2, int &r3) { int n; IN(n); string text[3]; int r[3]; REP(i,3) { IN(r[i]); IN.SkipWS(); text[i].resize(n); REP(j,n) { char c; IN(c); assert(c=='0' || c=='1'); text[i][j] = c; } } int cnt[2][2] = {}; REP(i,n) { ++cnt[text[0][i] != text[1][i]][text[0][i] != text[2][i]]; } r1 = r[0]; r2 = r[1]; r3 = r[2]; a = cnt[0][0]; b = cnt[1][0]; c = cnt[0][1]; d = cnt[1][1]; } vector<vector<Mod>> binomial_table; void compute_binomial_table(vector<int> ns) { sort(ns.begin(), ns.end()); assert(!ns.empty()); binomial_table.resize(ns.back() + 1); vector<Mod> row; vector<Mod> next_row; row.reserve(ns.back()+1); next_row.reserve(ns.back()+1); int n = 0; row = {Mod{1}}; auto next = ns.begin(); while (next != ns.end()) { if (*next == n) { binomial_table[n] = row; while (next != ns.end() && *next == n) ++next; } ++n; next_row.resize(n+1); next_row[0] = Mod{1}; FOR(k,1,n-1) next_row[k] = row[k-1] + row[k]; next_row[n] = Mod{1}; swap(row, next_row); } } inline Mod binomial(int n, int k) { return k < 0 || k > n ? Mod{0} : binomial_table[n][k]; } Mod One(int a, int r) { Mod res = 0; FOR(x,0,r) res += binomial(a,x); return res; } Mod Two(int a, int b, int r1, int r2) { // sum_x[A] = sum_(x<A) binomial(a,x) // 0 <= x <= a so 0 <= A <= a+1 vector<Mod> sum_x(a+2); sum_x[0] = 0; FOR(A, 1, a+1) sum_x[A] = sum_x[A-1] + binomial(a, A-1); Mod res = 0; FOR(y,0,b) { int A = min(r1-y, r2-b+y)+1; if (A<0) A=0; if (A>a+1) A=a+1; res += binomial(b,y) * sum_x[A]; } return res; } Mod Three(int a, int b, int c, int d, int r1, int r2, int r3) { // sum_xy(A,B) = sum_(x+y < A, x-y < B) binomial(a,x) * binomial(b,y) // 0 <= x+y <= a+b, so 0 <= A <= a+b+1 // -b <= x-y <= a, so -b <= B <= a+1 Array2d<Mod> sum_xy(a+b+2, a+b+2, -b); FOR(A, 1, a+b+1) { FOR(B, -b+1, a+1) { Mod s = sum_xy(A-1, B); s += sum_xy(A, B-1); s -= sum_xy(A-1, B-1); if (((A+B)&1) == 0) { // x+y = A-1 // x-y = B-1 int x = (A+B-2)>>1; int y = (A-B)>>1; s += binomial(a,x) * binomial(b,y); } sum_xy(A, B) = s; } } Mod res = 0; FOR(z, 0, c) { Mod sum_t = 0; FOR(t, 0, d) { int A = min(r1-z-t, r3-c-d+z+t) + 1; if (A<0) A=0; if (A>a+b+1) A=a+b+1; int B = r2-b-d-z+t + 1; if (B<-b) B=-b; if (B>a+1) B=a+1; sum_t += binomial(d, t) * sum_xy(A, B); } res += binomial(c, z) * sum_t; } return res; } int main() { int a,b,c,d; int r1,r2,r3; read_input(a,b,c,d,r1,r2,r3); compute_binomial_table({a,b,c,d,a+b,a+c,a+d,b+c,b+d,c+d,a+b+c+d}); Mod result = 0; result += One(a+b+c+d,r1); result += One(a+b+c+d,r2); result += One(a+b+c+d,r3); result -= Two(a+c,b+d,r1,r2); result -= Two(a+b,c+d,r1,r3); result -= Two(a+d,b+c,r2,r3); result += Three(a,b,c,d,r1,r2,r3); cout << result.get() << '\n'; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 | #include <bits/stdc++.h> #include <unistd.h> using namespace std; #define REP(i,n) for(int _n=(n), i=0;i<_n;++i) #define FOR(i,a,b) for(int i=(a),_b=(b);i<=_b;++i) #define FORD(i,a,b) for(int i=(a),_b=(b);i>=_b;--i) #define TRACE(x) cerr << "TRACE(" #x ")" << endl; #define DEBUG(x) cerr << #x << " = " << (x) << endl; typedef long long LL; typedef unsigned long long ULL; class Input { public: Input() { bufpos = bufend = buffer; eof = false; } bool Eof() { return eof; } char Peek() { if(bufpos == bufend) Grab(); return *bufpos; } unsigned char UPeek() { return static_cast<unsigned char>(Peek()); } void SkipWS(); template<class T> T Get(); void operator()() {} template<class Arg, class... Args> void operator()(Arg &arg, Args &... args) { arg = Get<Arg>(); operator()(args...); } private: static const int BUFSIZE = 1<<16; char buffer[BUFSIZE]; char *bufpos; char *bufend; bool eof; void Grab(); }; void Input::Grab() { if(eof) return; bufpos = buffer; bufend = buffer + read(0, buffer, BUFSIZE); if(bufend==bufpos) { eof=true; *bufpos=0; } } template<> inline char Input::Get<char>() { char res = Peek(); ++bufpos; return res; } void Input::SkipWS() { while(isspace(UPeek())) Get<char>(); } template<> unsigned Input::Get<unsigned>() { SkipWS(); unsigned x = 0; while(isdigit(UPeek())) { x = 10u * x + (Get<char>()-'0'); } return x; } template<> int Input::Get<int>() { SkipWS(); bool neg = false; if(Peek()=='-') { neg=true; Get<char>(); } unsigned x = Get<unsigned>(); if (neg) x = -x; return static_cast<int>(x); } Input IN; template<unsigned MOD> class Modulo { unsigned v; public: Modulo(unsigned x=0):v(x) {} unsigned get() const { return v; } Modulo operator+(Modulo b) const { unsigned res = v+b.v; if (res >= MOD) res -= MOD; return res; } void operator+=(Modulo b) { *this = *this + b; } Modulo operator-(Modulo b) const { return *this + Modulo(MOD-b.v); } void operator-=(Modulo b) { *this = *this - b; } Modulo operator*(Modulo b) const { return Modulo(ULL(v) * ULL(b.v) % MOD); } void operator*=(Modulo b) { *this = *this * b; } }; // [0..size1-1][base2 .. base2+size2-1] template <typename T> class Array2d { public: Array2d(int _size1, int _size2, int _base2) : size1(_size1), size2(_size2), base2(_base2), data(size1 * size2) {} T &operator()(int i, int j) { return data[i * size2 + j - base2]; } private: int size1; int size2; int base2; vector<T> data; }; using Mod = Modulo<1'000'000'007>; void read_input(int &a, int &b, int &c, int &d, int &r1, int &r2, int &r3) { int n; IN(n); string text[3]; int r[3]; REP(i,3) { IN(r[i]); IN.SkipWS(); text[i].resize(n); REP(j,n) { char c; IN(c); assert(c=='0' || c=='1'); text[i][j] = c; } } int cnt[2][2] = {}; REP(i,n) { ++cnt[text[0][i] != text[1][i]][text[0][i] != text[2][i]]; } r1 = r[0]; r2 = r[1]; r3 = r[2]; a = cnt[0][0]; b = cnt[1][0]; c = cnt[0][1]; d = cnt[1][1]; } vector<vector<Mod>> binomial_table; void compute_binomial_table(vector<int> ns) { sort(ns.begin(), ns.end()); assert(!ns.empty()); binomial_table.resize(ns.back() + 1); vector<Mod> row; vector<Mod> next_row; row.reserve(ns.back()+1); next_row.reserve(ns.back()+1); int n = 0; row = {Mod{1}}; auto next = ns.begin(); while (next != ns.end()) { if (*next == n) { binomial_table[n] = row; while (next != ns.end() && *next == n) ++next; } ++n; next_row.resize(n+1); next_row[0] = Mod{1}; FOR(k,1,n-1) next_row[k] = row[k-1] + row[k]; next_row[n] = Mod{1}; swap(row, next_row); } } inline Mod binomial(int n, int k) { return k < 0 || k > n ? Mod{0} : binomial_table[n][k]; } Mod One(int a, int r) { Mod res = 0; FOR(x,0,r) res += binomial(a,x); return res; } Mod Two(int a, int b, int r1, int r2) { // sum_x[A] = sum_(x<A) binomial(a,x) // 0 <= x <= a so 0 <= A <= a+1 vector<Mod> sum_x(a+2); sum_x[0] = 0; FOR(A, 1, a+1) sum_x[A] = sum_x[A-1] + binomial(a, A-1); Mod res = 0; FOR(y,0,b) { int A = min(r1-y, r2-b+y)+1; if (A<0) A=0; if (A>a+1) A=a+1; res += binomial(b,y) * sum_x[A]; } return res; } Mod Three(int a, int b, int c, int d, int r1, int r2, int r3) { // sum_xy(A,B) = sum_(x+y < A, x-y < B) binomial(a,x) * binomial(b,y) // 0 <= x+y <= a+b, so 0 <= A <= a+b+1 // -b <= x-y <= a, so -b <= B <= a+1 Array2d<Mod> sum_xy(a+b+2, a+b+2, -b); FOR(A, 1, a+b+1) { FOR(B, -b+1, a+1) { Mod s = sum_xy(A-1, B); s += sum_xy(A, B-1); s -= sum_xy(A-1, B-1); if (((A+B)&1) == 0) { // x+y = A-1 // x-y = B-1 int x = (A+B-2)>>1; int y = (A-B)>>1; s += binomial(a,x) * binomial(b,y); } sum_xy(A, B) = s; } } Mod res = 0; FOR(z, 0, c) { Mod sum_t = 0; FOR(t, 0, d) { int A = min(r1-z-t, r3-c-d+z+t) + 1; if (A<0) A=0; if (A>a+b+1) A=a+b+1; int B = r2-b-d-z+t + 1; if (B<-b) B=-b; if (B>a+1) B=a+1; sum_t += binomial(d, t) * sum_xy(A, B); } res += binomial(c, z) * sum_t; } return res; } int main() { int a,b,c,d; int r1,r2,r3; read_input(a,b,c,d,r1,r2,r3); compute_binomial_table({a,b,c,d,a+b,a+c,a+d,b+c,b+d,c+d,a+b+c+d}); Mod result = 0; result += One(a+b+c+d,r1); result += One(a+b+c+d,r2); result += One(a+b+c+d,r3); result -= Two(a+c,b+d,r1,r2); result -= Two(a+b,c+d,r1,r3); result -= Two(a+d,b+c,r2,r3); result += Three(a,b,c,d,r1,r2,r3); cout << result.get() << '\n'; } |