#include <cstdio> #include <cstdlib> #include <cstring> using namespace std; #define MOD 1000000007 int n; int r1,r2,r3; // Extended Euclidean algorithm int xGCD(int a, int b, int &x, int &y) { if (b == 0) { x = 1; y = 0; return a; } int x1, y1, gcd = xGCD(b, a % b, x1, y1); x = y1; y = x1 - (long long)(a / b) * y1; return gcd; } // factorial of n modulo MOD int modfact(int n) { int result = 1; while (n > 1) { result = (long long)result * n % MOD; n -= 1; } return result; } // multiply a and b modulo MOD int modmult(int a, int b) { return (long long)a * b % MOD; } // inverse of a modulo MOD int inverse(int a) { int x, y; xGCD(a, MOD, x, y); return x; } // binomial coefficient nCk modulo MOD int bc(int n, int k) { return modmult(modmult(modfact(n), inverse(modfact(k))), inverse(modfact(n - k))) + MOD; } int size(int r) { int result = 0; for (int i=0;i<=r;i++) { result = (result + bc(n, i)) % MOD; } return result; } int count1(char *s) { int r = 0; for(int i=0;i<n;i++) { if(s[i] == '1') r++; } return r; } int diff(char *s1, char*s2) { int r = 0; for(int i=0;i<n;i++) { if(s1[i] != s2[i]) r++; } return r; } int intersect2(int r1, char* s1, int r2, char* s2) { int dif = diff(s1,s2); // wspolny srodek if (dif == 0) { if( r1 < r2) return size(r1); else return size(r2); } // rozdzielne if (dif > r1 + r2) return 0; // pierwsza zawiera druga if (r1 >= dif + r2) return size(r2); // druga zawiera pierwszą if (r2 >= dif + r1) return size(r1); // przecinają sie int result = 0; for(int i=dif - r2; i<=r1; i++) { result = (result + bc(dif, i)) % MOD; } return result; } int main() { scanf("%d", &n); char* s1 = new char[n](); char* s2 = new char[n](); char* s3 = new char[n](); scanf("%d %s", &r1, s1); scanf("%d %s", &r2, s2); scanf("%d %s", &r3, s3); // identyczne 3 if (r1 == r2 && r2 == r3 && strcmp(s1,s2) == 0 && strcmp(s2,s3) == 0) { printf("%d\n", size(r1)); return 0; } if (r1 == r2 && strcmp(s1,s2) == 0) { // pierwsza i druga identyczne printf("%d\n", (size(r1) + size(r3) - intersect2(r1,s1,r3,s3)) % MOD); // nie biore drugiej } else if (r1 == r2 && strcmp(s1,s3) == 0) { // pierwsza i trzecia identyczne printf("%d\n", (size(r1) + size(r2) - intersect2(r1,s1,r2,s2)) % MOD); // nie biore trzeciej } else if (r2 == r3 && strcmp(s2,s3) == 0) { // druga i trzecia identyczne printf("%d\n", (size(r1) + size(r2) - intersect2(r1,s1,r2,s2)) % MOD); // nie biore trzeciej } else { // printf("%d %d %d\n", size(r1),size(r2) , size(r3)); // printf("%d \n", intersect2(r1,s1,r2,s2)); // printf("%d \n", intersect2(r1,s1,r3,s3)); // printf("%d \n", intersect2(r2,s2,r3,s3)); // int result = (size(r1) + size(r2) + size(r3)) % MOD; result = (result - intersect2(r1,s1,r2,s2)) % MOD; result = (result - intersect2(r1,s1,r3,s3)) % MOD; result = (result - intersect2(r2,s2,r3,s3)) % MOD; printf("%d\n", result); } }
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 | #include <cstdio> #include <cstdlib> #include <cstring> using namespace std; #define MOD 1000000007 int n; int r1,r2,r3; // Extended Euclidean algorithm int xGCD(int a, int b, int &x, int &y) { if (b == 0) { x = 1; y = 0; return a; } int x1, y1, gcd = xGCD(b, a % b, x1, y1); x = y1; y = x1 - (long long)(a / b) * y1; return gcd; } // factorial of n modulo MOD int modfact(int n) { int result = 1; while (n > 1) { result = (long long)result * n % MOD; n -= 1; } return result; } // multiply a and b modulo MOD int modmult(int a, int b) { return (long long)a * b % MOD; } // inverse of a modulo MOD int inverse(int a) { int x, y; xGCD(a, MOD, x, y); return x; } // binomial coefficient nCk modulo MOD int bc(int n, int k) { return modmult(modmult(modfact(n), inverse(modfact(k))), inverse(modfact(n - k))) + MOD; } int size(int r) { int result = 0; for (int i=0;i<=r;i++) { result = (result + bc(n, i)) % MOD; } return result; } int count1(char *s) { int r = 0; for(int i=0;i<n;i++) { if(s[i] == '1') r++; } return r; } int diff(char *s1, char*s2) { int r = 0; for(int i=0;i<n;i++) { if(s1[i] != s2[i]) r++; } return r; } int intersect2(int r1, char* s1, int r2, char* s2) { int dif = diff(s1,s2); // wspolny srodek if (dif == 0) { if( r1 < r2) return size(r1); else return size(r2); } // rozdzielne if (dif > r1 + r2) return 0; // pierwsza zawiera druga if (r1 >= dif + r2) return size(r2); // druga zawiera pierwszą if (r2 >= dif + r1) return size(r1); // przecinają sie int result = 0; for(int i=dif - r2; i<=r1; i++) { result = (result + bc(dif, i)) % MOD; } return result; } int main() { scanf("%d", &n); char* s1 = new char[n](); char* s2 = new char[n](); char* s3 = new char[n](); scanf("%d %s", &r1, s1); scanf("%d %s", &r2, s2); scanf("%d %s", &r3, s3); // identyczne 3 if (r1 == r2 && r2 == r3 && strcmp(s1,s2) == 0 && strcmp(s2,s3) == 0) { printf("%d\n", size(r1)); return 0; } if (r1 == r2 && strcmp(s1,s2) == 0) { // pierwsza i druga identyczne printf("%d\n", (size(r1) + size(r3) - intersect2(r1,s1,r3,s3)) % MOD); // nie biore drugiej } else if (r1 == r2 && strcmp(s1,s3) == 0) { // pierwsza i trzecia identyczne printf("%d\n", (size(r1) + size(r2) - intersect2(r1,s1,r2,s2)) % MOD); // nie biore trzeciej } else if (r2 == r3 && strcmp(s2,s3) == 0) { // druga i trzecia identyczne printf("%d\n", (size(r1) + size(r2) - intersect2(r1,s1,r2,s2)) % MOD); // nie biore trzeciej } else { // printf("%d %d %d\n", size(r1),size(r2) , size(r3)); // printf("%d \n", intersect2(r1,s1,r2,s2)); // printf("%d \n", intersect2(r1,s1,r3,s3)); // printf("%d \n", intersect2(r2,s2,r3,s3)); // int result = (size(r1) + size(r2) + size(r3)) % MOD; result = (result - intersect2(r1,s1,r2,s2)) % MOD; result = (result - intersect2(r1,s1,r3,s3)) % MOD; result = (result - intersect2(r2,s2,r3,s3)) % MOD; printf("%d\n", result); } } |