void transpose(mat_GF2E& X, const mat_GF2E& A) { long n = A.NumRows(); long m = A.NumCols(); long i, j; if (&X == & A) { if (n == m) for (i = 1; i <= n; i++) for (j = i+1; j <= n; j++) swap(X(i, j), X(j, i)); else { mat_GF2E tmp; tmp.SetDims(m, n); for (i = 1; i <= n; i++) for (j = 1; j <= m; j++) tmp(j, i) = A(i, j); X.kill(); X = tmp; } } else { X.SetDims(m, n); for (i = 1; i <= n; i++) for (j = 1; j <= m; j++) X(j, i) = A(i, j); } }
void power(mat_GF2E& X, const mat_GF2E& A, const ZZ& e) { if (A.NumRows() != A.NumCols()) LogicError("power: non-square matrix"); if (e == 0) { ident(X, A.NumRows()); return; } mat_GF2E T1, T2; long i, k; k = NumBits(e); T1 = A; for (i = k-2; i >= 0; i--) { sqr(T2, T1); if (bit(e, i)) mul(T1, T2, A); else T1 = T2; } if (e < 0) inv(X, T1); else X = T1; }
void mul_aux(mat_GF2E& X, const mat_GF2E& A, const mat_GF2E& B) { long n = A.NumRows(); long l = A.NumCols(); long m = B.NumCols(); if (l != B.NumRows()) LogicError("matrix mul: dimension mismatch"); X.SetDims(n, m); long i, j, k; GF2X acc, tmp; for (i = 1; i <= n; i++) { for (j = 1; j <= m; j++) { clear(acc); for(k = 1; k <= l; k++) { mul(tmp, rep(A(i,k)), rep(B(k,j))); add(acc, acc, tmp); } conv(X(i,j), acc); } } }
void applyLookupTable(vec_GF2E& ltable, mat_GF2E& tgt){ int i,j,n=tgt.NumRows(),m=tgt.NumCols(); for(i=0; i<n; i++){ for(j=0; j<m; j++){ tgt[i][j] = ltable[getLong(tgt[i][j])]; } } }
void mul(mat_GF2E& X, const mat_GF2E& A, const GF2E& b_in) { GF2E b = b_in; long n = A.NumRows(); long m = A.NumCols(); X.SetDims(n, m); long i, j; for (i = 0; i < n; i++) for (j = 0; j < m; j++) mul(X[i][j], A[i][j], b); }
void add(mat_GF2E& X, const mat_GF2E& A, const mat_GF2E& B) { long n = A.NumRows(); long m = A.NumCols(); if (B.NumRows() != n || B.NumCols() != m) Error("matrix add: dimension mismatch"); X.SetDims(n, m); long i, j; for (i = 1; i <= n; i++) for (j = 1; j <= m; j++) add(X(i,j), A(i,j), B(i,j)); }
void clear(mat_GF2E& x) { long n = x.NumRows(); long i; for (i = 0; i < n; i++) clear(x[i]); }
long IsIdent(const mat_GF2E& A, long n) { if (A.NumRows() != n || A.NumCols() != n) return 0; long i, j; for (i = 1; i <= n; i++) for (j = 1; j <= n; j++) if (i != j) { if (!IsZero(A(i, j))) return 0; } else { if (!IsOne(A(i, j))) return 0; } return 1; }
long IsDiag(const mat_GF2E& A, long n, const GF2E& d) { if (A.NumRows() != n || A.NumCols() != n) return 0; long i, j; for (i = 1; i <= n; i++) for (j = 1; j <= n; j++) if (i != j) { if (!IsZero(A(i, j))) return 0; } else { if (A(i, j) != d) return 0; } return 1; }
void mul(vec_GF2E& x, const mat_GF2E& A, const vec_GF2E& b) { if (&b == &x || A.position1(x) != -1) { vec_GF2E tmp; mul_aux(tmp, A, b); x = tmp; } else mul_aux(x, A, b); }
long IsZero(const mat_GF2E& a) { long n = a.NumRows(); long i; for (i = 0; i < n; i++) if (!IsZero(a[i])) return 0; return 1; }
void ident(mat_GF2E& X, long n) { X.SetDims(n, n); long i, j; for (i = 1; i <= n; i++) for (j = 1; j <= n; j++) if (i == j) set(X(i, j)); else clear(X(i, j)); }
void diag(mat_GF2E& X, long n, const GF2E& d_in) { GF2E d = d_in; X.SetDims(n, n); long i, j; for (i = 1; i <= n; i++) for (j = 1; j <= n; j++) if (i == j) X(i, j) = d; else clear(X(i, j)); }
static void mul_aux(vec_GF2E& x, const mat_GF2E& A, const vec_GF2E& b) { long n = A.NumRows(); long l = A.NumCols(); if (l != b.length()) LogicError("matrix mul: dimension mismatch"); x.SetLength(n); long i, k; GF2X acc, tmp; for (i = 1; i <= n; i++) { clear(acc); for (k = 1; k <= l; k++) { mul(tmp, rep(A(i,k)), rep(b(k))); add(acc, acc, tmp); } conv(x(i), acc); } }
static void mul_aux(vec_GF2E& x, const vec_GF2E& a, const mat_GF2E& B) { long n = B.NumRows(); long l = B.NumCols(); if (n != a.length()) LogicError("matrix mul: dimension mismatch"); x.SetLength(l); long i, k; GF2X acc, tmp; for (i = 1; i <= l; i++) { clear(acc); for (k = 1; k <= n; k++) { mul(tmp, rep(a(k)), rep(B(k,i))); add(acc, acc, tmp); } conv(x(i), acc); } }
void buildLinPolyMatrix(mat_GF2E& M, long p) { assert(p == 2); long d = GF2E::degree(); M.SetDims(d, d); for (long j = 0; j < d; j++) conv(M[0][j], GF2X(j, 1)); for (long i = 1; i < d; i++) for (long j = 0; j < d; j++) M[i][j] = power(M[i-1][j], p); }
void kernel(mat_GF2E& X, const mat_GF2E& A) { long m = A.NumRows(); long n = A.NumCols(); mat_GF2E M; long r; transpose(M, A); r = gauss(M); X.SetDims(m-r, m); long i, j, k, s; GF2X t1, t2; GF2E T3; vec_long D; D.SetLength(m); for (j = 0; j < m; j++) D[j] = -1; vec_GF2E inverses; inverses.SetLength(m); j = -1; for (i = 0; i < r; i++) { do { j++; } while (IsZero(M[i][j])); D[j] = i; inv(inverses[j], M[i][j]); } for (k = 0; k < m-r; k++) { vec_GF2E& v = X[k]; long pos = 0; for (j = m-1; j >= 0; j--) { if (D[j] == -1) { if (pos == k) set(v[j]); else clear(v[j]); pos++; } else { i = D[j]; clear(t1); for (s = j+1; s < m; s++) { mul(t2, rep(v[s]), rep(M[i][s])); add(t1, t1, t2); } conv(T3, t1); mul(T3, T3, inverses[j]); v[j] = T3; } } } }
void determinant(GF2E& d, const mat_GF2E& M_in) { long k, n; long i, j; long pos; GF2X t1, t2; GF2X *x, *y; const GF2XModulus& p = GF2E::modulus(); n = M_in.NumRows(); if (M_in.NumCols() != n) LogicError("determinant: nonsquare matrix"); if (n == 0) { set(d); return; } vec_GF2XVec M; M.SetLength(n); for (i = 0; i < n; i++) { M[i].SetSize(n, 2*GF2E::WordLength()); for (j = 0; j < n; j++) M[i][j] = rep(M_in[i][j]); } GF2X det; set(det); for (k = 0; k < n; k++) { pos = -1; for (i = k; i < n; i++) { rem(t1, M[i][k], p); M[i][k] = t1; if (pos == -1 && !IsZero(t1)) pos = i; } if (pos != -1) { if (k != pos) { swap(M[pos], M[k]); } MulMod(det, det, M[k][k], p); // make M[k, k] == -1 mod p, and make row k reduced InvMod(t1, M[k][k], p); for (j = k+1; j < n; j++) { rem(t2, M[k][j], p); MulMod(M[k][j], t2, t1, p); } for (i = k+1; i < n; i++) { // M[i] = M[i] + M[k]*M[i,k] t1 = M[i][k]; // this is already reduced x = M[i].elts() + (k+1); y = M[k].elts() + (k+1); for (j = k+1; j < n; j++, x++, y++) { // *x = *x + (*y)*t1 mul(t2, *y, t1); add(*x, *x, t2); } } } else { clear(d); return; } } conv(d, det); }
static void solve_impl(GF2E& d, vec_GF2E& X, const mat_GF2E& A, const vec_GF2E& b, bool trans) { long n = A.NumRows(); if (A.NumCols() != n) LogicError("solve: nonsquare matrix"); if (b.length() != n) LogicError("solve: dimension mismatch"); if (n == 0) { set(d); X.SetLength(0); return; } long i, j, k, pos; GF2X t1, t2; GF2X *x, *y; const GF2XModulus& p = GF2E::modulus(); vec_GF2XVec M; M.SetLength(n); for (i = 0; i < n; i++) { M[i].SetSize(n+1, 2*GF2E::WordLength()); if (trans) for (j = 0; j < n; j++) M[i][j] = rep(A[j][i]); else for (j = 0; j < n; j++) M[i][j] = rep(A[i][j]); M[i][n] = rep(b[i]); } GF2X det; set(det); for (k = 0; k < n; k++) { pos = -1; for (i = k; i < n; i++) { rem(t1, M[i][k], p); M[i][k] = t1; if (pos == -1 && !IsZero(t1)) { pos = i; } } if (pos != -1) { if (k != pos) { swap(M[pos], M[k]); } MulMod(det, det, M[k][k], p); // make M[k, k] == -1 mod p, and make row k reduced InvMod(t1, M[k][k], p); for (j = k+1; j <= n; j++) { rem(t2, M[k][j], p); MulMod(M[k][j], t2, t1, p); } for (i = k+1; i < n; i++) { // M[i] = M[i] + M[k]*M[i,k] t1 = M[i][k]; // this is already reduced x = M[i].elts() + (k+1); y = M[k].elts() + (k+1); for (j = k+1; j <= n; j++, x++, y++) { // *x = *x + (*y)*t1 mul(t2, *y, t1); add(*x, *x, t2); } } } else { clear(d); return; } } X.SetLength(n); for (i = n-1; i >= 0; i--) { clear(t1); for (j = i+1; j < n; j++) { mul(t2, rep(X[j]), M[i][j]); add(t1, t1, t2); } add(t1, t1, M[i][n]); conv(X[i], t1); } conv(d, det); }
void inv(GF2E& d, mat_GF2E& X, const mat_GF2E& A) { long n = A.NumRows(); if (A.NumCols() != n) LogicError("inv: nonsquare matrix"); if (n == 0) { set(d); X.SetDims(0, 0); return; } long i, j, k, pos; GF2X t1, t2; GF2X *x, *y; const GF2XModulus& p = GF2E::modulus(); vec_GF2XVec M; M.SetLength(n); for (i = 0; i < n; i++) { M[i].SetSize(2*n, 2*GF2E::WordLength()); for (j = 0; j < n; j++) { M[i][j] = rep(A[i][j]); clear(M[i][n+j]); } set(M[i][n+i]); } GF2X det; set(det); for (k = 0; k < n; k++) { pos = -1; for (i = k; i < n; i++) { rem(t1, M[i][k], p); M[i][k] = t1; if (pos == -1 && !IsZero(t1)) { pos = i; } } if (pos != -1) { if (k != pos) { swap(M[pos], M[k]); } MulMod(det, det, M[k][k], p); // make M[k, k] == -1 mod p, and make row k reduced InvMod(t1, M[k][k], p); for (j = k+1; j < 2*n; j++) { rem(t2, M[k][j], p); MulMod(M[k][j], t2, t1, p); } for (i = k+1; i < n; i++) { // M[i] = M[i] + M[k]*M[i,k] t1 = M[i][k]; // this is already reduced x = M[i].elts() + (k+1); y = M[k].elts() + (k+1); for (j = k+1; j < 2*n; j++, x++, y++) { // *x = *x + (*y)*t1 mul(t2, *y, t1); add(*x, *x, t2); } } } else { clear(d); return; } } X.SetDims(n, n); for (k = 0; k < n; k++) { for (i = n-1; i >= 0; i--) { clear(t1); for (j = i+1; j < n; j++) { mul(t2, rep(X[j][k]), M[i][j]); add(t1, t1, t2); } add(t1, t1, M[i][n+k]); conv(X[i][k], t1); } } conv(d, det); }
long gauss(mat_GF2E& M_in, long w) { long k, l; long i, j; long pos; GF2X t1, t2, t3; GF2X *x, *y; long n = M_in.NumRows(); long m = M_in.NumCols(); if (w < 0 || w > m) LogicError("gauss: bad args"); const GF2XModulus& p = GF2E::modulus(); vec_GF2XVec M; M.SetLength(n); for (i = 0; i < n; i++) { M[i].SetSize(m, 2*GF2E::WordLength()); for (j = 0; j < m; j++) { M[i][j] = rep(M_in[i][j]); } } l = 0; for (k = 0; k < w && l < n; k++) { pos = -1; for (i = l; i < n; i++) { rem(t1, M[i][k], p); M[i][k] = t1; if (pos == -1 && !IsZero(t1)) { pos = i; } } if (pos != -1) { swap(M[pos], M[l]); InvMod(t3, M[l][k], p); for (j = k+1; j < m; j++) { rem(M[l][j], M[l][j], p); } for (i = l+1; i < n; i++) { // M[i] = M[i] + M[l]*M[i,k]*t3 MulMod(t1, M[i][k], t3, p); clear(M[i][k]); x = M[i].elts() + (k+1); y = M[l].elts() + (k+1); for (j = k+1; j < m; j++, x++, y++) { // *x = *x + (*y)*t1 mul(t2, *y, t1); add(t2, t2, *x); *x = t2; } } l++; } } for (i = 0; i < n; i++) for (j = 0; j < m; j++) conv(M_in[i][j], M[i][j]); return l; }
long gauss(mat_GF2E& M) { return gauss(M, M.NumCols()); }