#include<iostream> #include<bits/stdc++.h> using namespace std; #define MOD 1000000007 // A Lucas Theorem based solution to compute nCr % p // Returns nCr % p. In this Lucas Theorem based program, // this function is only called for n < p and r < p. int difference(string a, string b){ int R=0; for(int i=0; i< a.size(); i++){ if (a[i]!=b[i]){ R++; } } return R; } int nCrModpDP(int n, int r, int p) { // The array C is going to store last row of // pascal triangle at the end. And last entry // of last row is nCr int C[r+1]; memset(C, 0, sizeof(C)); C[0] = 1; // Top row of Pascal Triangle // One by constructs remaining rows of Pascal // Triangle from top to bottom for (int i = 1; i <= n; i++) { // Fill entries of current row using previous // row values for (int j = min(i, r); j > 0; j--) // nCj = (n-1)Cj + (n-1)C(j-1); C[j] = (C[j] + C[j-1])%p; } return C[r]; } int pow(int x, int n){ int wy = x; if(n==0){ return 1; } for(int i = 1; i<n; i++){ x= (x*wy)%MOD; } return x; } int value_of_hiper(int r, int n){ int sum = 0; for(int i=0; i<=r; i++){ sum = (sum+nCrModpDP(n,i,MOD)%MOD); } return sum; } int intersection2( int r_1, int r_2, int R, int W){ int sum=0; int r_min; int r_max; if(r_1>r_2){ r_max=r_1; r_min =r_2; }else{ r_max=r_2; r_min=r_1; } int W_count = 0; while(r_min+r_max>=R){ int W_sum = nCrModpDP(W, W_count, MOD); int R_sum = 0; int t_r_max = r_max; int t_r_min = r_min; while(t_r_max+t_r_min>=R){ if(t_r_min>=R){ R_sum = (R_sum + pow(2,R))%MOD; break; }else{ R_sum = (R_sum + nCrModpDP(R, t_r_min, MOD)); t_r_min--; } } sum = (sum + (W_sum*R_sum)%MOD)%MOD; W_count++; r_max--; r_min--; } return sum; } int main(){ int n; cin >> n; int sum; int r_a; int r_b; int r_c; string hiper_a; string hiper_b; string hiper_c; cin >> r_a >> hiper_a; cin >> r_b >> hiper_b; cin >> r_c >> hiper_c; bool same = false; int r_d; int r_e; string hiper_d; string hiper_e; if(r_a==r_b and hiper_a==hiper_b){ r_d = r_a; hiper_d = hiper_a; r_e = r_c; hiper_e = hiper_c; same = true; }else if(r_b==r_c and hiper_b==hiper_c){ r_d = r_b; hiper_d = hiper_b; r_e = r_a; hiper_e = hiper_a; same = true; }else if(r_c==r_a and hiper_c==hiper_a){ r_d = r_c; hiper_d = hiper_c; r_e = r_b; hiper_e = hiper_b; same = true; } if(same){ int R_DE = difference(hiper_d,hiper_e); int W_DE = hiper_d.size() - R_DE; sum = (sum + value_of_hiper(r_d, n))%MOD; sum = (sum + value_of_hiper(r_e, n))%MOD; sum = (sum - intersection2(r_d,r_e,R_DE,W_DE))%MOD; }else{ int R_AB = difference(hiper_a,hiper_b); int W_AB = hiper_a.size() - R_AB; int R_BC = difference(hiper_b,hiper_c); int W_BC = hiper_b.size() - R_BC; int R_CA = difference(hiper_c,hiper_a); int W_CA = hiper_c.size() - R_CA; sum = (sum + value_of_hiper(r_a, n))%MOD; //cout << sum << endl; sum = (sum + value_of_hiper(r_b, n))%MOD; //cout << sum << endl; sum = (sum + value_of_hiper(r_c, n))%MOD; //cout << sum << endl; sum = (sum - intersection2(r_a,r_b,R_AB,W_AB))%MOD; //cout << sum << endl; sum = (sum - intersection2(r_b,r_c,R_BC,W_BC))%MOD; //cout << sum << endl; sum = (sum - intersection2(r_c,r_a,R_CA,W_CA))%MOD; } cout << sum << endl; }
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 | #include<iostream> #include<bits/stdc++.h> using namespace std; #define MOD 1000000007 // A Lucas Theorem based solution to compute nCr % p // Returns nCr % p. In this Lucas Theorem based program, // this function is only called for n < p and r < p. int difference(string a, string b){ int R=0; for(int i=0; i< a.size(); i++){ if (a[i]!=b[i]){ R++; } } return R; } int nCrModpDP(int n, int r, int p) { // The array C is going to store last row of // pascal triangle at the end. And last entry // of last row is nCr int C[r+1]; memset(C, 0, sizeof(C)); C[0] = 1; // Top row of Pascal Triangle // One by constructs remaining rows of Pascal // Triangle from top to bottom for (int i = 1; i <= n; i++) { // Fill entries of current row using previous // row values for (int j = min(i, r); j > 0; j--) // nCj = (n-1)Cj + (n-1)C(j-1); C[j] = (C[j] + C[j-1])%p; } return C[r]; } int pow(int x, int n){ int wy = x; if(n==0){ return 1; } for(int i = 1; i<n; i++){ x= (x*wy)%MOD; } return x; } int value_of_hiper(int r, int n){ int sum = 0; for(int i=0; i<=r; i++){ sum = (sum+nCrModpDP(n,i,MOD)%MOD); } return sum; } int intersection2( int r_1, int r_2, int R, int W){ int sum=0; int r_min; int r_max; if(r_1>r_2){ r_max=r_1; r_min =r_2; }else{ r_max=r_2; r_min=r_1; } int W_count = 0; while(r_min+r_max>=R){ int W_sum = nCrModpDP(W, W_count, MOD); int R_sum = 0; int t_r_max = r_max; int t_r_min = r_min; while(t_r_max+t_r_min>=R){ if(t_r_min>=R){ R_sum = (R_sum + pow(2,R))%MOD; break; }else{ R_sum = (R_sum + nCrModpDP(R, t_r_min, MOD)); t_r_min--; } } sum = (sum + (W_sum*R_sum)%MOD)%MOD; W_count++; r_max--; r_min--; } return sum; } int main(){ int n; cin >> n; int sum; int r_a; int r_b; int r_c; string hiper_a; string hiper_b; string hiper_c; cin >> r_a >> hiper_a; cin >> r_b >> hiper_b; cin >> r_c >> hiper_c; bool same = false; int r_d; int r_e; string hiper_d; string hiper_e; if(r_a==r_b and hiper_a==hiper_b){ r_d = r_a; hiper_d = hiper_a; r_e = r_c; hiper_e = hiper_c; same = true; }else if(r_b==r_c and hiper_b==hiper_c){ r_d = r_b; hiper_d = hiper_b; r_e = r_a; hiper_e = hiper_a; same = true; }else if(r_c==r_a and hiper_c==hiper_a){ r_d = r_c; hiper_d = hiper_c; r_e = r_b; hiper_e = hiper_b; same = true; } if(same){ int R_DE = difference(hiper_d,hiper_e); int W_DE = hiper_d.size() - R_DE; sum = (sum + value_of_hiper(r_d, n))%MOD; sum = (sum + value_of_hiper(r_e, n))%MOD; sum = (sum - intersection2(r_d,r_e,R_DE,W_DE))%MOD; }else{ int R_AB = difference(hiper_a,hiper_b); int W_AB = hiper_a.size() - R_AB; int R_BC = difference(hiper_b,hiper_c); int W_BC = hiper_b.size() - R_BC; int R_CA = difference(hiper_c,hiper_a); int W_CA = hiper_c.size() - R_CA; sum = (sum + value_of_hiper(r_a, n))%MOD; //cout << sum << endl; sum = (sum + value_of_hiper(r_b, n))%MOD; //cout << sum << endl; sum = (sum + value_of_hiper(r_c, n))%MOD; //cout << sum << endl; sum = (sum - intersection2(r_a,r_b,R_AB,W_AB))%MOD; //cout << sum << endl; sum = (sum - intersection2(r_b,r_c,R_BC,W_BC))%MOD; //cout << sum << endl; sum = (sum - intersection2(r_c,r_a,R_CA,W_CA))%MOD; } cout << sum << endl; } |