WIP: Make tc::Group header-only

(except for tc::Group::subgroup, since it needs full definition of tc::Group _and_ tc::SubGroup)
This commit is contained in:
David Allemang
2022-02-24 17:49:39 -05:00
parent 4ec96cd155
commit 2d2feb3256
6 changed files with 283 additions and 315 deletions

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@@ -1,8 +1,11 @@
add_library(tc
include/tc/groups.hpp
src/groups.cpp
include/tc/core.hpp
include/tc/cosets.hpp
include/tc/group.hpp
include/tc/groups.hpp
include/tc/util.hpp
src/core.cpp
src/groups.cpp
src/solve.cpp)
target_include_directories(tc PUBLIC include)

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@@ -5,161 +5,6 @@
#include <vector>
#include <string>
namespace tc {
struct Action {
int from_idx = -1;
int gen = -1;
Action() = default;
Action(const Action &) = default;
Action(int from_idx, int gen);
};
struct Path {
std::vector<Action> path;
Path() = default;
Path(const Path &) = default;
void add_row();
[[nodiscard]] Action get(int to_idx) const;
void put(int from_idx, int gen, int to_idx);
template<class C, class T, class E>
void walk(
C& res,
T start,
std::vector<E> gens,
std::function<T(const T &, const E &)> op
) const {
size_t s = size();
res.reserve(s);
res.push_back(start);
for (int i = 1; i < s; ++i) {
auto &action = path[i];
auto &from = res.get(action.from_idx);
auto &val = gens[action.gen];
res.push_back(op(from,val));
}
}
template<class T, class E>
[[nodiscard]] std::vector<T> walk(
T start,
std::vector<E> gens,
std::function<T(const T &, const E &)> op
) const {
std::vector<T> res;
res.reserve(size());
res.push_back(start);
for (int i = 1; i < size(); ++i) {
auto &action = path[i];
auto &from = res[action.from_idx];
auto &val = gens[action.gen];
res.push_back(op(from, val));
}
return res;
}
template<class T>
[[nodiscard]] std::vector<T> walk(
T start,
std::function<T(const T &, const int &)> op
) const {
std::vector<T> res;
res.reserve(size());
res.push_back(start);
for (int i = 1; i < size(); ++i) {
auto &action = path[i];
auto &from = res[action.from_idx];
auto &val = action.gen;
res[i] = op(from, val);
}
return res;
}
[[nodiscard]] size_t size() const;
};
struct Cosets {
int ngens;
std::vector<int> data;
Path path;
Cosets(const Cosets &) = default;
explicit Cosets(int ngens);
void add_row();
void put(int coset, int gen, int target);
void put(int idx, int target);
[[nodiscard]] int get(int coset, int gen) const;
[[nodiscard]] int get(int idx) const;
[[nodiscard]] size_t size() const;
};
struct Rel {
std::array<int, 2> gens;
int mult;
Rel() = default;
Rel(const Rel &) = default;
Rel(int a, int b, int m);
[[nodiscard]] Rel shift(int off) const;
};
struct SubGroup;
struct Group {
int ngens;
std::vector<std::vector<int>> _mults;
std::string name;
Group(const Group &) = default;
explicit Group(int ngens, const std::vector<Rel> &rels = {}, std::string name = "G");
void set(const Rel &r);
[[nodiscard]] int get(int a, int b) const;
[[nodiscard]] std::vector<Rel> rels() const;
[[nodiscard]] SubGroup subgroup(const std::vector<int> &gens) const;
[[nodiscard]] Group product(const Group &other) const;
[[nodiscard]] Group power(int p) const;
[[nodiscard]] Cosets solve(const std::vector<int> &sub_gens = {}) const;
};
struct SubGroup : public Group {
std::vector<int> gen_map;
const Group &parent;
SubGroup(const Group &parent, std::vector<int> gen_map);
};
Group operator*(const Group &g, const Group &h);
Group operator^(const Group &g, int p);
}
#include "util.hpp"
#include "cosets.hpp"
#include "group.hpp"

56
tc/include/tc/cosets.hpp Normal file
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@@ -0,0 +1,56 @@
#pragma once
#include <cstdlib>
#include "cosets.hpp"
namespace tc {
struct Cosets {
int ngens;
std::vector<int> data;
Path path;
Cosets(const Cosets &) = default;
explicit Cosets(int ngens)
: ngens(ngens) {
}
void add_row() {
data.resize(data.size() + ngens, -1);
path.add_row();
}
void put(int coset, int gen, int target) {
data[coset * ngens + gen] = target;
data[target * ngens + gen] = coset;
if (path.get(target).from_idx == -1) {
path.put(coset, gen, target);
}
}
void put(int idx, int target) {
int coset = idx / ngens;
int gen = idx % ngens;
data[idx] = target;
data[target * ngens + gen] = coset;
if (path.get(target).from_idx == -1) {
path.put(coset, gen, target);
}
}
[[nodiscard]] int get(int coset, int gen) const {
return data[coset * ngens + gen];
}
[[nodiscard]] int get(int idx) const {
return data[idx];
}
[[nodiscard]] size_t size() const {
return path.size();
}
};
}

98
tc/include/tc/group.hpp Normal file
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@@ -0,0 +1,98 @@
#pragma once
#include <sstream>
namespace tc {
struct Group;
struct SubGroup;
struct Group {
int ngens;
std::vector<std::vector<int>> _mults;
std::string name;
Group(const Group &) = default;
explicit Group(int ngens, const std::vector<Rel> &rels = {}, std::string name = "G")
: ngens(ngens), name(std::move(name)) {
_mults.resize(ngens);
for (auto &mult: _mults) {
mult.resize(ngens, 2);
}
for (const auto &rel: rels) {
set(rel);
}
}
void set(const Rel &r) {
_mults[r.gens[0]][r.gens[1]] = r.mult;
_mults[r.gens[1]][r.gens[0]] = r.mult;
}
[[nodiscard]] int get(int a, int b) const {
return _mults[a][b];
}
[[nodiscard]] std::vector<Rel> rels() const {
std::vector<Rel> res;
for (int i = 0; i < ngens - 1; ++i) {
for (int j = i + 1; j < ngens; ++j) {
res.emplace_back(i, j, get(i, j));
}
}
return res;
}
[[nodiscard]] SubGroup subgroup(const std::vector<int> &gens) const;
[[nodiscard]] Group product(const Group &other) const {
std::stringstream ss;
ss << name << "*" << other.name;
Group g(ngens + other.ngens, rels(), ss.str());
for (const auto &rel: other.rels()) {
g.set(rel.shift(ngens));
}
return g;
}
[[nodiscard]] Group power(int p) const {
std::stringstream ss;
ss << name << "^" << p;
Group g(ngens * p, {}, ss.str());
for (const auto &rel: rels()) {
for (int off = 0; off < g.ngens; off += ngens) {
g.set(rel.shift(off));
}
}
return g;
}
[[nodiscard]] Cosets solve(const std::vector<int> &sub_gens = {}) const;
};
struct SubGroup : public Group {
std::vector<int> gen_map;
const Group &parent;
SubGroup(const Group &parent, std::vector<int> gen_map)
: Group(gen_map.size()), parent(parent), gen_map() {
std::sort(gen_map.begin(), gen_map.end());
this->gen_map = gen_map;
for (size_t i = 0; i < gen_map.size(); ++i) {
for (size_t j = 0; j < gen_map.size(); ++j) {
int mult = parent.get(gen_map[i], gen_map[j]);
set(Rel(i, j, mult));
}
}
}
};
}

120
tc/include/tc/util.hpp Normal file
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@@ -0,0 +1,120 @@
#pragma once
#include <cstdlib>
#include <vector>
#include <algorithm>
#include <functional>
namespace tc {
struct Action {
int from_idx = -1;
int gen = -1;
Action() = default;
Action(const Action &) = default;
Action(int from_idx, int gen)
: from_idx(from_idx), gen(gen) {
}
};
struct Path {
std::vector<Action> path;
Path() = default;
Path(const Path &) = default;
void add_row() {
path.resize(path.size() + 1);
}
[[nodiscard]] Action get(int to_idx) const {
return path[to_idx];
}
void put(int from_idx, int gen, int to_idx) {
path[to_idx] = Action(from_idx, gen);
}
template<class C, class T, class E>
void walk(
C &res,
T start,
std::vector<E> gens,
std::function<T(const T &, const E &)> op
) const {
size_t s = size();
res.reserve(s);
res.push_back(start);
for (int i = 1; i < s; ++i) {
auto &action = path[i];
auto &from = res.get(action.from_idx);
auto &val = gens[action.gen];
res.push_back(op(from, val));
}
}
template<class T, class E>
[[nodiscard]] std::vector<T> walk(
T start,
std::vector<E> gens,
std::function<T(const T &, const E &)> op
) const {
std::vector<T> res;
res.reserve(size());
res.push_back(start);
for (int i = 1; i < size(); ++i) {
auto &action = path[i];
auto &from = res[action.from_idx];
auto &val = gens[action.gen];
res.push_back(op(from, val));
}
return res;
}
template<class T>
[[nodiscard]] std::vector<T> walk(
T start,
std::function<T(const T &, const int &)> op
) const {
std::vector<T> res;
res.reserve(size());
res.push_back(start);
for (int i = 1; i < size(); ++i) {
auto &action = path[i];
auto &from = res[action.from_idx];
auto &val = action.gen;
res[i] = op(from, val);
}
return res;
}
[[nodiscard]] size_t size() const {
return path.size();
}
};
struct Rel {
std::array<int, 2> gens;
int mult;
Rel() = default;
Rel(const Rel &) = default;
Rel(int a, int b, int m)
: gens({a, b}), mult(m) {
}
[[nodiscard]] Rel shift(int off) const {
return Rel(gens[0] + off, gens[1] + off, mult);
}
};
}

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@@ -1,161 +1,7 @@
#include "tc/core.hpp"
#include <utility>
#include <sstream>
#include <algorithm>
#include <tc/core.hpp>
namespace tc {
Action::Action(int from_idx, int gen)
: from_idx(from_idx), gen(gen) {
}
void Path::add_row() {
path.resize(path.size() + 1);
}
Action Path::get(int to_idx) const {
return path[to_idx];
}
void Path::put(int from_idx, int gen, int to_idx) {
path[to_idx] = Action(from_idx, gen);
}
size_t Path::size() const {
return path.size();
}
Cosets::Cosets(int ngens)
: ngens(ngens) {
}
void Cosets::add_row() {
data.resize(data.size() + ngens, -1);
path.add_row();
}
void Cosets::put(int coset, int gen, int target) {
data[coset * ngens + gen] = target;
data[target * ngens + gen] = coset;
if (path.get(target).from_idx == -1) {
path.put(coset, gen, target);
}
}
void Cosets::put(int idx, int target) {
int coset = idx / ngens;
int gen = idx % ngens;
data[idx] = target;
data[target * ngens + gen] = coset;
if (path.get(target).from_idx == -1) {
path.put(coset, gen, target);
}
}
int Cosets::get(int coset, int gen) const {
return data[coset * ngens + gen];
}
int Cosets::get(int idx) const {
return data[idx];
}
size_t Cosets::size() const {
return path.size();
}
Rel::Rel(int a, int b, int m)
: gens({a, b}), mult(m) {
}
Rel Rel::shift(int off) const {
return Rel(gens[0] + off, gens[1] + off, mult);
}
Group::Group(int ngens, const std::vector<Rel> &rels, std::string name)
: ngens(ngens), name(std::move(name)) {
_mults.resize(ngens);
for (auto &mult : _mults) {
mult.resize(ngens, 2);
}
for (const auto &rel : rels) {
set(rel);
}
}
void Group::set(const Rel &r) {
_mults[r.gens[0]][r.gens[1]] = r.mult;
_mults[r.gens[1]][r.gens[0]] = r.mult;
}
int Group::get(int a, int b) const {
return _mults[a][b];
}
std::vector<Rel> Group::rels() const {
std::vector<Rel> res;
for (int i = 0; i < ngens - 1; ++i) {
for (int j = i + 1; j < ngens; ++j) {
res.emplace_back(i, j, get(i, j));
}
}
return res;
}
SubGroup Group::subgroup(const std::vector<int> &gens) const {
return SubGroup(*this, gens);
}
Group Group::product(const Group &other) const {
std::stringstream ss;
ss << name << "*" << other.name;
Group g(ngens + other.ngens, rels(), ss.str());
for (const auto &rel : other.rels()) {
g.set(rel.shift(ngens));
}
return g;
}
Group Group::power(int p) const {
std::stringstream ss;
ss << name << "^" << p;
Group g(ngens * p, {}, ss.str());
for (const auto &rel : rels()) {
for (int off = 0; off < g.ngens; off += ngens) {
g.set(rel.shift(off));
}
}
return g;
}
SubGroup::SubGroup(const Group &parent, std::vector<int> gen_map)
: Group(gen_map.size()), parent(parent) {
std::sort(gen_map.begin(), gen_map.end());
this->gen_map = gen_map;
for (size_t i = 0; i < gen_map.size(); ++i) {
for (size_t j = 0; j < gen_map.size(); ++j) {
int mult = parent.get(gen_map[i], gen_map[j]);
set(Rel(i, j, mult));
}
}
}
Group operator*(const Group &g, const Group &h) {
return g.product(h);
}
Group operator^(const Group &g, int p) {
return g.power(p);
}
}