public static GcdFraction gcd(long[] xs0, long[] xs1, int nx, long[] ys0, long[] ys1, int ny) {
nx = highest(xs0, 0, nx);
ny = highest(ys0, 0, ny);
if (nx == 0 || ny == 0) {
throw new IllegalArgumentException(dividesByZero("x or y"));
} else if (nx < ny) {
long[] zs0 = xs0;
long[] zs1 = xs1;
int nz = nx;
xs0 = ys0;
xs1 = ys1;
nx = ny;
ys0 = zs0;
ys1 = zs1;
ny = nz;
}
while (0 < ny) {
int nr = Euclid.divides(xs0, xs1, nx, ys0, ys1, ny);
long[] rs0 = xs0;
long[] rs1 = xs1;
nr = highest(rs0, 0, nr);
// Arrays.fill(rs0, nr, nx, 0);
xs0 = ys0;
xs1 = ys1;
nx = ny;
ys0 = rs0;
ys1 = rs1;
ny = nr;
}
return new GcdFraction(xs0, xs1, nx);
}
public static GcdLong gcd(long[] xs, int nx, long[] ys, int ny) {
nx = highest(xs, 0, nx);
ny = highest(ys, 0, ny);
if (nx == 0 || ny == 0) {
throw new IllegalArgumentException(dividesByZero("x or y"));
} else if (nx < ny) {
long[] zs = xs;
int nz = nx;
xs = ys;
nx = ny;
ys = zs;
ny = nz;
}
while (0 < ny) {
int nr = Euclid.divides(xs, nx, ys, ny);
long[] rs = xs;
nr = highest(rs, 0, nr);
// Arrays.fill(rs, nr, nx, 0);
xs = ys;
nx = ny;
ys = rs;
ny = nr;
}
return new GcdLong(xs, nx);
}
protected static void reduce(long[] xs0, long[] xs1, int ind, boolean gcd) {
if (xs0[ind] == 0) {
xs1[ind] = 1;
} else if (xs0[ind] == xs1[ind]) {
xs0[ind] = 1;
xs1[ind] = 1;
} else if (xs0[ind] == -xs1[ind]) {
xs0[ind] = -1;
xs1[ind] = 1;
} else if (xs0[ind] % xs1[ind] == 0) {
xs0[ind] = xs0[ind] / xs1[ind];
xs1[ind] = 1;
} else {
if (xs1[ind] < 0) {
xs0[ind] = -xs0[ind];
xs1[ind] = -xs1[ind];
}
if (gcd) {
long g = Euclid.gcd(Math.abs(xs0[ind]), xs1[ind]);
if (g != 1) {
xs0[ind] /= g;
xs1[ind] /= g;
}
}
}
}
public static String toString(long[] xs, int begin, int end, String var) {
StringBuilder buffer = new StringBuilder();
try {
if (!Euclid.toString(buffer, xs, begin, end, var)) {
buffer.append("0");
}
} catch (IOException ex) {
ex.printStackTrace();
}
return buffer.toString();
}
public static String toString(long[] xs, String var) {
return Euclid.toString(xs, 0, xs.length, var);
}