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Array::randomAll; ordered/distinct random pairs
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@ifsmirnov
ifsmirnov committed Mar 23, 2017
1 parent f1a88f7 commit 04acb48
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Showing 4 changed files with 158 additions and 26 deletions.
41 changes: 41 additions & 0 deletions array.h
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Original file line number Diff line number Diff line change
Expand Up @@ -58,11 +58,15 @@ class GenericArray : public ReprProxy<GenericArray<T>>, public std::vector<T> {
template<typename F, typename ...Args>
static GenericArray<T> randomfUnique(
size_t size, F func, const Args& ... args);
template<typename F, typename ...Args>
static GenericArray<T> randomfAll(F func, const Args& ... args);

template<typename ...Args>
static GenericArray<T> random(size_t size, const Args& ... args);
template<typename ...Args>
static GenericArray<T> randomUnique(size_t size, const Args& ... args);
template<typename ...Args>
static GenericArray<T> randomAll(const Args& ... args);

static GenericArray<T> id(size_t size, T start = T{});

Expand Down Expand Up @@ -184,6 +188,43 @@ GenericArray<T> GenericArray<T>::randomUnique(
args...);
}

template<typename T>
template<typename F, typename ...Args>
GenericArray<T> GenericArray<T>::randomfAll(
F func,
const Args& ... args)
{
typename detail::DictContainer<T>::type set;
GenericArray<T> result;

int timeAfterLastHit = 0;

while (true) {
T t = func(args...);
if (!set.count(t)) {
set.insert(t);
result.push_back(t);
timeAfterLastHit = 0;
}

++timeAfterLastHit;

// Probability of finding not all elements is about e^{-20} ~= 1e-9
if (timeAfterLastHit > (result.size() + 10) * 20) {
return result;
}
}
}

template<typename T>
template<typename ...Args>
GenericArray<T> GenericArray<T>::randomAll(const Args& ... args)
{
return GenericArray<T>::randomfAll(
[](Args... args) { return rnd.tnext<T>(args...); },
args...);
}

template<typename T>
GenericArray<T> GenericArray<T>::id(size_t size, T start) {
constexpr bool enable = std::is_integral<T>::value;
Expand Down
92 changes: 79 additions & 13 deletions jngen.h
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Original file line number Diff line number Diff line change
Expand Up @@ -830,30 +830,43 @@ struct TypedRandom : public BaseTypedRandom {
T next(Args... args) { return random.next(args...); }
};

struct OrderedPairTag {} opair;
struct RandomPairTraits {
const bool ordered;
const bool distinct;
};

RandomPairTraits opair{true, false};
RandomPairTraits dpair{false, true};
RandomPairTraits odpair{true, true};
RandomPairTraits dopair{true, true};

template<>
struct TypedRandom<std::pair<int, int>> : public BaseTypedRandom {
using BaseTypedRandom::BaseTypedRandom;

std::pair<int, int> next(int n) {
// can't write 'return {random.next(n), random.next(n)}' because order of
// evaluation of function arguments is unspecified.
int first = random.next(n);
int second = random.next(n);
return {first, second};
return next(n, {false, false});
}
std::pair<int, int> next(int l, int r) {
int first = random.next(l, r);
int second = random.next(l, r);
return {first, second};
return next(l, r, {false, false});
}

std::pair<int, int> next(int n, OrderedPairTag) {
return ordered(next(n));
std::pair<int, int> next(int n, RandomPairTraits traits) {
int first = rnd.next(n);
int second;
do {
second = rnd.next(n);
} while (traits.distinct && first == second);
if (traits.ordered && first > second) {
std::swap(first, second);
}
return {first, second};
}
std::pair<int, int> next(int l, int r, OrderedPairTag) {
return ordered(next(l, r));
std::pair<int, int> next(int l, int r, RandomPairTraits traits) {
auto res = next(r-l+1, traits);
res.first += l;
res.second += l;
return res;
}

private:
Expand All @@ -871,6 +884,9 @@ using jngen::Random;

using jngen::rnd;
using jngen::opair;
using jngen::dpair;
using jngen::dopair;
using jngen::odpair;

void registerGen(int argc, char *argv[], int version = 1) {
(void)version; // unused, only for testlib.h compatibility
Expand Down Expand Up @@ -1438,11 +1454,15 @@ class GenericArray : public ReprProxy<GenericArray<T>>, public std::vector<T> {
template<typename F, typename ...Args>
static GenericArray<T> randomfUnique(
size_t size, F func, const Args& ... args);
template<typename F, typename ...Args>
static GenericArray<T> randomfAll(F func, const Args& ... args);

template<typename ...Args>
static GenericArray<T> random(size_t size, const Args& ... args);
template<typename ...Args>
static GenericArray<T> randomUnique(size_t size, const Args& ... args);
template<typename ...Args>
static GenericArray<T> randomAll(const Args& ... args);

static GenericArray<T> id(size_t size, T start = T{});

Expand Down Expand Up @@ -1564,6 +1584,43 @@ GenericArray<T> GenericArray<T>::randomUnique(
args...);
}

template<typename T>
template<typename F, typename ...Args>
GenericArray<T> GenericArray<T>::randomfAll(
F func,
const Args& ... args)
{
typename detail::DictContainer<T>::type set;
GenericArray<T> result;

int timeAfterLastHit = 0;

while (true) {
T t = func(args...);
if (!set.count(t)) {
set.insert(t);
result.push_back(t);
timeAfterLastHit = 0;
}

++timeAfterLastHit;

// Probability of finding not all elements is about e^{-20} ~= 1e-9
if (timeAfterLastHit > (result.size() + 10) * 20) {
return result;
}
}
}

template<typename T>
template<typename ...Args>
GenericArray<T> GenericArray<T>::randomAll(const Args& ... args)
{
return GenericArray<T>::randomfAll(
[](Args... args) { return rnd.tnext<T>(args...); },
args...);
}

template<typename T>
GenericArray<T> GenericArray<T>::id(size_t size, T start) {
constexpr bool enable = std::is_integral<T>::value;
Expand Down Expand Up @@ -2058,6 +2115,15 @@ class ArrayRandom {
typedef decltype(func(args...)) T;
return GenericArray<T>::randomfUnique(size, func, args...);
}

template<typename F, typename ...Args>
static auto randomfAll(
F func,
Args... args) -> GenericArray<decltype(func(args...))>
{
typedef decltype(func(args...)) T;
return GenericArray<T>::randomfAll(size, func, args...);
}
} rnda;

} // namespace jngen
Expand Down
42 changes: 29 additions & 13 deletions random.h
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Original file line number Diff line number Diff line change
Expand Up @@ -246,30 +246,43 @@ struct TypedRandom : public BaseTypedRandom {
T next(Args... args) { return random.next(args...); }
};

struct OrderedPairTag {} opair;
struct RandomPairTraits {
const bool ordered;
const bool distinct;
};

RandomPairTraits opair{true, false};
RandomPairTraits dpair{false, true};
RandomPairTraits odpair{true, true};
RandomPairTraits dopair{true, true};

template<>
struct TypedRandom<std::pair<int, int>> : public BaseTypedRandom {
using BaseTypedRandom::BaseTypedRandom;

std::pair<int, int> next(int n) {
// can't write 'return {random.next(n), random.next(n)}' because order of
// evaluation of function arguments is unspecified.
int first = random.next(n);
int second = random.next(n);
return {first, second};
return next(n, {false, false});
}
std::pair<int, int> next(int l, int r) {
int first = random.next(l, r);
int second = random.next(l, r);
return {first, second};
return next(l, r, {false, false});
}

std::pair<int, int> next(int n, OrderedPairTag) {
return ordered(next(n));
std::pair<int, int> next(int n, RandomPairTraits traits) {
int first = rnd.next(n);
int second;
do {
second = rnd.next(n);
} while (traits.distinct && first == second);
if (traits.ordered && first > second) {
std::swap(first, second);
}
return {first, second};
}
std::pair<int, int> next(int l, int r, OrderedPairTag) {
return ordered(next(l, r));
std::pair<int, int> next(int l, int r, RandomPairTraits traits) {
auto res = next(r-l+1, traits);
res.first += l;
res.second += l;
return res;
}

private:
Expand All @@ -287,6 +300,9 @@ using jngen::Random;

using jngen::rnd;
using jngen::opair;
using jngen::dpair;
using jngen::dopair;
using jngen::odpair;

void registerGen(int argc, char *argv[], int version = 1) {
(void)version; // unused, only for testlib.h compatibility
Expand Down
9 changes: 9 additions & 0 deletions rnda.h
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Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,15 @@ class ArrayRandom {
typedef decltype(func(args...)) T;
return GenericArray<T>::randomfUnique(size, func, args...);
}

template<typename F, typename ...Args>
static auto randomfAll(
F func,
Args... args) -> GenericArray<decltype(func(args...))>
{
typedef decltype(func(args...)) T;
return GenericArray<T>::randomfAll(size, func, args...);
}
} rnda;

} // namespace jngen
Expand Down

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