#include <bits/stdc++.h> using namespace std; const size_t LIM = 200; typedef bitset<LIM> BS; struct Bitmat { // column-major internally BS bs[LIM]; // the operator is row-major BS::reference operator[](const pair<size_t, size_t> X) { return bs[X.second][X.first]; } void print(size_t n = LIM) { for(size_t i = 0; i < n; ++i) { for(size_t j = 0; j < n; ++j) printf("%d", int((*this)[{i, j}])); printf("\n"); } printf("\n"); } /* void inplaceTranspose() { for(size_t i = 0; i < LIM; ++i) for(size_t j = i+1; j < LIM; ++j) { auto a = (*this)[{i, j}]; auto b = (*this)[{j, i}]; // swap a with b a = a^b; b = b^a; a = a^b; } } void inplaceSqr() { Bitmat M(*this), T(*this); T.inplaceTranspose(); for(size_t i = 0; i < LIM; ++i) for(size_t j = 0; j < LIM; ++j) (*this)[{i, j}] = (T.bs[i] & M.bs[j]).any(); } */ }; struct Bitvec { // horizontal (transposed) BS bs; BS::reference operator[](size_t x) { return bs[x]; } void print(size_t n = LIM) { for(size_t i = 0; i < n; ++i) printf("%d", int((*this)[i])); printf("\n\n"); } Bitvec & operator*=(const Bitmat &M) { Bitvec w(*this); for(size_t i = 0; i < LIM; ++i) (*this)[i] = (w.bs & M.bs[i]).any(); return *this; } }; int main() { int n, b, r; scanf("%d%d%d", &n, &b, &r); Bitmat M; { char buf[LIM+1]; for(size_t i = 0; i < n; ++i) { scanf("%s", buf); for(size_t j = 0; buf[j]; ++j) M[{i, j}] = (buf[j] == '1'); } } Bitvec v; for(size_t i = 0; i < r; ++i) { int q; scanf("%d", &q); v[q-1] = 1; } // v.print(n); // M.print(n); unordered_set<BS> us; BS mask; for(size_t i = 0; i < b; ++i) mask[i] = 1; mask.flip(); while(!us.count(v.bs)) { us.insert(v.bs); v *= M; if((v.bs & mask).none()) { printf("%d\n", int(us.size())); return 0; } } printf("-1\n"); /* Bitmat Mp(M); for(size_t i = 0; i < 200; ++i) { if(i < 10) Mp.print(n); Mp.inplaceSqr(); } // Mp == M**2**200 */ return 0; }
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 | #include <bits/stdc++.h> using namespace std; const size_t LIM = 200; typedef bitset<LIM> BS; struct Bitmat { // column-major internally BS bs[LIM]; // the operator is row-major BS::reference operator[](const pair<size_t, size_t> X) { return bs[X.second][X.first]; } void print(size_t n = LIM) { for(size_t i = 0; i < n; ++i) { for(size_t j = 0; j < n; ++j) printf("%d", int((*this)[{i, j}])); printf("\n"); } printf("\n"); } /* void inplaceTranspose() { for(size_t i = 0; i < LIM; ++i) for(size_t j = i+1; j < LIM; ++j) { auto a = (*this)[{i, j}]; auto b = (*this)[{j, i}]; // swap a with b a = a^b; b = b^a; a = a^b; } } void inplaceSqr() { Bitmat M(*this), T(*this); T.inplaceTranspose(); for(size_t i = 0; i < LIM; ++i) for(size_t j = 0; j < LIM; ++j) (*this)[{i, j}] = (T.bs[i] & M.bs[j]).any(); } */ }; struct Bitvec { // horizontal (transposed) BS bs; BS::reference operator[](size_t x) { return bs[x]; } void print(size_t n = LIM) { for(size_t i = 0; i < n; ++i) printf("%d", int((*this)[i])); printf("\n\n"); } Bitvec & operator*=(const Bitmat &M) { Bitvec w(*this); for(size_t i = 0; i < LIM; ++i) (*this)[i] = (w.bs & M.bs[i]).any(); return *this; } }; int main() { int n, b, r; scanf("%d%d%d", &n, &b, &r); Bitmat M; { char buf[LIM+1]; for(size_t i = 0; i < n; ++i) { scanf("%s", buf); for(size_t j = 0; buf[j]; ++j) M[{i, j}] = (buf[j] == '1'); } } Bitvec v; for(size_t i = 0; i < r; ++i) { int q; scanf("%d", &q); v[q-1] = 1; } // v.print(n); // M.print(n); unordered_set<BS> us; BS mask; for(size_t i = 0; i < b; ++i) mask[i] = 1; mask.flip(); while(!us.count(v.bs)) { us.insert(v.bs); v *= M; if((v.bs & mask).none()) { printf("%d\n", int(us.size())); return 0; } } printf("-1\n"); /* Bitmat Mp(M); for(size_t i = 0; i < 200; ++i) { if(i < 10) Mp.print(n); Mp.inplaceSqr(); } // Mp == M**2**200 */ return 0; } |