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Correct performance regression in StrategySupportProfile #742

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Merged
tturocy merged 6 commits into from
Jan 26, 2026
Merged

Correct performance regression in StrategySupportProfile #742

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cfb137d
Preparatory internal renaming
tturocy Jan 26, 2026
d3bd17d
Re-fill m_support and modify on add/remove
tturocy Jan 26, 2026
6b19772
Re-add iterators based on strategy vector directly.
tturocy Jan 26, 2026
38e5675
Use const_iterator directly
tturocy Jan 26, 2026
4fa27ed
A few optimisations
tturocy Jan 26, 2026
29f5440
Fix declaration
tturocy Jan 26, 2026
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10 changes: 5 additions & 5 deletions src/games/gametable.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -115,17 +115,17 @@ template <class T> class TableMixedStrategyProfileRep : public MixedStrategyProf
T &value) const;
//@}

const CartesianProductSpace &m_pureStrategies;

long StrategyOffset(const GameStrategy &s) const
{
const auto &space = this->GetSupport().GetGame()->m_pureStrategies;
const auto &player = s->GetPlayer();
const size_t i = player->GetNumber() - 1;
return (s->GetNumber() - 1) * space.m_strides[i];
return (s->GetNumber() - 1) * m_pureStrategies.m_strides[s->m_player->GetNumber() - 1];
}

public:
explicit TableMixedStrategyProfileRep(const StrategySupportProfile &p_support)
: MixedStrategyProfileRep<T>(p_support)
: MixedStrategyProfileRep<T>(p_support),
m_pureStrategies(p_support.GetGame()->m_pureStrategies)
{
}
~TableMixedStrategyProfileRep() override = default;
Expand Down
56 changes: 39 additions & 17 deletions src/games/stratspt.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -35,20 +35,26 @@ namespace Gambit {
StrategySupportProfile::StrategySupportProfile(const Game &p_game) : m_game(p_game)
{
m_game->BuildComputedValues();
m_strategies.m_space = &p_game->m_pureStrategies;
m_strategies.m_allowedDigits.resize(p_game->NumPlayers());
for (const auto &player : m_game->GetPlayers()) {
for (const auto &strategy : player->GetStrategies()) {
m_support[player].push_back(strategy);
}
}

m_strategyDigits.m_space = &p_game->m_pureStrategies;
m_strategyDigits.m_allowedDigits.resize(p_game->NumPlayers());

for (size_t i = 0; i < p_game->NumPlayers(); ++i) {
const int radix = p_game->m_pureStrategies.m_radices[i];
auto &digits = m_strategies.m_allowedDigits[i];
auto &digits = m_strategyDigits.m_allowedDigits[i];
digits.resize(radix);
std::iota(digits.begin(), digits.end(), 0);
}
}

int StrategySupportProfile::MixedProfileLength() const
{
return sum_function(m_strategies.m_allowedDigits, [](const std::vector<int> &digits) {
return sum_function(m_strategyDigits.m_allowedDigits, [](const std::vector<int> &digits) {
return static_cast<int>(digits.size());
});
}
Expand All @@ -68,8 +74,8 @@ bool StrategySupportProfile::IsSubsetOf(const StrategySupportProfile &p_other) c
if (m_game != p_other.m_game) {
return false;
}
const auto &A = m_strategies.m_allowedDigits;
const auto &B = p_other.m_strategies.m_allowedDigits;
const auto &A = m_strategyDigits.m_allowedDigits;
const auto &B = p_other.m_strategyDigits.m_allowedDigits;
const size_t n = A.size();

for (size_t i = 0; i < n; ++i) {
Expand Down Expand Up @@ -112,12 +118,22 @@ void StrategySupportProfile::AddStrategy(const GameStrategy &p_strategy)
if (p_strategy->GetGame() != m_game) {
throw MismatchException();
}

auto &support = m_support[p_strategy->GetPlayer()];
auto pos = std::find_if(support.begin(), support.end(), [p_strategy](const GameStrategy &s) {
return s->GetNumber() >= p_strategy->GetNumber();
});
if (pos == support.end() || *pos != p_strategy) {
// Strategy is not in the support for the player; add at this location to keep sorted by number
support.insert(pos, p_strategy);
}

const size_t index = p_strategy->GetPlayer()->GetNumber() - 1;
const int digit = p_strategy->GetNumber() - 1;
auto &digits = m_strategies.m_allowedDigits[index];
auto pos = std::lower_bound(digits.begin(), digits.end(), digit);
if (pos == digits.end() || *pos != digit) {
digits.insert(pos, digit);
auto &digits = m_strategyDigits.m_allowedDigits[index];
auto ipos = std::lower_bound(digits.begin(), digits.end(), digit);
if (ipos == digits.end() || *ipos != digit) {
digits.insert(ipos, digit);
}
}

Expand All @@ -126,15 +142,21 @@ bool StrategySupportProfile::RemoveStrategy(const GameStrategy &p_strategy)
if (p_strategy->GetGame() != m_game) {
throw MismatchException();
}
const size_t index = p_strategy->GetPlayer()->GetNumber() - 1;
const int digit = p_strategy->GetNumber() - 1;
auto &digits = m_strategies.m_allowedDigits[index];
if (digits.size() == 1) {
auto &support = m_support[p_strategy->GetPlayer()];
if (support.size() == 1) {
return false;
}
auto pos = std::lower_bound(digits.begin(), digits.end(), digit);
if (pos != digits.end() && *pos == digit) {
digits.erase(pos);
auto pos = std::find(support.begin(), support.end(), p_strategy);
if (pos != support.end()) {
support.erase(pos);
}

const size_t index = p_strategy->GetPlayer()->GetNumber() - 1;
const int digit = p_strategy->GetNumber() - 1;
auto &digits = m_strategyDigits.m_allowedDigits[index];
auto ipos = std::lower_bound(digits.begin(), digits.end(), digit);
if (ipos != digits.end() && *ipos == digit) {
digits.erase(ipos);
return true;
}
return false;
Expand Down
92 changes: 18 additions & 74 deletions src/games/stratspt.h
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Original file line number Diff line number Diff line change
Expand Up @@ -40,88 +40,32 @@ namespace Gambit {
/// in which they appear in the underlying game.
class StrategySupportProfile {
Game m_game;
CartesianSubset m_strategies;
std::map<GamePlayer, std::vector<GameStrategy>> m_support;
CartesianSubset m_strategyDigits;

public:
class Support {
const StrategySupportProfile *m_profile;
size_t m_playerIndex;
GamePlayer m_player;

public:
class const_iterator {
const StrategySupportProfile *m_profile{nullptr};
size_t m_playerIndex{0};
std::vector<int>::const_iterator m_it;

public:
using value_type = GameStrategy;
using reference = GameStrategy;
using pointer = void;
using difference_type = std::ptrdiff_t;
using iterator_category = std::forward_iterator_tag;

const_iterator() = default;
const_iterator(const StrategySupportProfile *profile, const size_t playerIndex,
const std::vector<int>::const_iterator it)
: m_profile(profile), m_playerIndex(playerIndex), m_it(it)
{
}

GameStrategy operator*() const
{
const auto &player = m_profile->m_game->GetPlayer(m_playerIndex + 1);
return player->GetStrategy(*m_it + 1);
}

const_iterator &operator++()
{
++m_it;
return *this;
}

bool operator==(const const_iterator &other) const { return m_it == other.m_it; }

bool operator!=(const const_iterator &other) const { return !(*this == other); }
};

Support() : m_profile(nullptr), m_playerIndex(0) {}

Support(const StrategySupportProfile *profile, GamePlayer player)
: m_profile(profile), m_playerIndex(player->GetNumber() - 1)
{
}

size_t size() const { return m_profile->m_strategies.m_allowedDigits[m_playerIndex].size(); }

GameStrategy operator[](const size_t index) const
{
const int digit = m_profile->m_strategies.m_allowedDigits[m_playerIndex][index];
return m_profile->m_game->GetPlayer(m_playerIndex + 1)->GetStrategy(digit + 1);
}
using const_iterator = std::vector<GameStrategy>::const_iterator;

GameStrategy front() const
Support() : m_profile(nullptr), m_player(nullptr) {}
Support(const StrategySupportProfile *profile, const GamePlayer &player)
: m_profile(profile), m_player(player)
{
const int digit = m_profile->m_strategies.m_allowedDigits[m_playerIndex].front();
return m_profile->m_game->GetPlayer(m_playerIndex + 1)->GetStrategy(digit + 1);
}

GameStrategy back() const
{
const int digit = m_profile->m_strategies.m_allowedDigits[m_playerIndex].back();
return m_profile->m_game->GetPlayer(m_playerIndex + 1)->GetStrategy(digit + 1);
}

const_iterator begin() const
{
const auto &digits = m_profile->m_strategies.m_allowedDigits[m_playerIndex];
return {m_profile, m_playerIndex, digits.begin()};
}

const_iterator end() const
size_t size() const { return m_profile->m_support.at(m_player).size(); }
GameStrategy operator[](const size_t index) const
{
const auto &digits = m_profile->m_strategies.m_allowedDigits[m_playerIndex];
return {m_profile, m_playerIndex, digits.end()};
return m_profile->m_support.at(m_player)[index];
}
GameStrategy front() const { return m_profile->m_support.at(m_player).front(); }
GameStrategy back() const { return m_profile->m_support.at(m_player).back(); }
const_iterator begin() const { return m_profile->m_support.at(m_player).begin(); }
const_iterator end() const { return m_profile->m_support.at(m_player).end(); }
};

/// @name Lifecycle
Expand All @@ -136,13 +80,13 @@ class StrategySupportProfile {
bool operator==(const StrategySupportProfile &p_support) const
{
return m_game == p_support.m_game &&
m_strategies.m_allowedDigits == p_support.m_strategies.m_allowedDigits;
m_strategyDigits.m_allowedDigits == p_support.m_strategyDigits.m_allowedDigits;
}
/// Test for the inequality of two supports
bool operator!=(const StrategySupportProfile &p_support) const
{
return m_game != p_support.m_game ||
m_strategies.m_allowedDigits != p_support.m_strategies.m_allowedDigits;
m_strategyDigits.m_allowedDigits != p_support.m_strategyDigits.m_allowedDigits;
}
//@}

Expand All @@ -166,7 +110,7 @@ class StrategySupportProfile {
/// Returns true exactly when the strategy is in the support.
bool Contains(const GameStrategy &s) const
{
const auto &digits = m_strategies.m_allowedDigits[s->GetPlayer()->GetNumber() - 1];
const auto &digits = m_strategyDigits.m_allowedDigits[s->GetPlayer()->GetNumber() - 1];
const int digit = s->GetNumber() - 1;
return std::binary_search(digits.begin(), digits.end(), digit);
}
Expand Down Expand Up @@ -203,7 +147,7 @@ class StrategySupportProfile {
const size_t player_index = player->GetNumber() - 1;
const int digit = p_strategy->GetNumber() - 1;
StrategySupportProfile restricted(*this);
restricted.m_strategies.m_allowedDigits[player_index].assign(1, digit);
restricted.m_strategyDigits.m_allowedDigits[player_index].assign(1, digit);
return restricted;
}
//@}
Expand Down