Data Structures That Make Video Games Go Roundhigh. 2 High variance. Elements are widely distributed between buckets.Open Addressing Hash Maps ● Simplest implementation only require a contiguous block of memory. ● Elements are more densely packed Addressing Hash Maps ● Simplest implementation only require a contiguous block of memory. ● Elements are more densely packed. ● Better cache performance. ● Collisions are resolved via probing. metadata about it’s probe sequence length, PSL and is defaulted to some value. 2. On insert, elements start with a PSL value of 0. 3. PSL of the inserted element is compared to the PSL of the bucket0 码力 | 196 页 | 3.03 MB | 5 月前3- Back to Basics: Classic 9STLSteagall Rationale • Data is almost always collections of elements • A virtually infinite number of data element types • Each collection of elements has some representation • A large number of possible O(1) Independent of number of elements Logarithmic O(log(n)) Increases logarithmically with the number of elements Linear O(n) Increases linearly with the number of elements N-log-N O(n*log(n)) Increases 2021 Bob Steagall Key Principles • Containers store collections of elements • Algorithms perform operations upon collections of elements • Containers and algorithms are entirely independent • Iterators0 码力 | 75 页 | 603.36 KB | 5 月前3
- Modern C++ IteratorsLoop Over Arrays • Two ways to iterate over the elements of an array – Using indexes – Using pointers int arr[] = {10, 20, 30, 40}; // iterate over elements with index: for (int i = 0; i < 4; ++i) { std::cout std::cout << arr[i] << '\n'; } // iterate over elements with pointer: for (int* p = arr; p < arr + 4; ++p) { std::cout << *p << '\n'; } Output: 10 20 30 40 10 20 30 40 30 40 10 20 arr: arr arr+2 josuttis.com 5 C++ Iterators: Generalization of Pointers that Iterate • Iterate like a pointer over elements – From begin() til end() std::vector
v{10, 20, 30, 40, 50, 60, 70}; for (std::vector ::iterator 0 码力 | 24 页 | 1.93 MB | 5 月前3 - Taming the C++ Filter View// print first three elements print(std::views::take(coll2, 3)); // print first three elements print(coll1 | std::views::take(3)); // print first three elements print(coll2 | std::views::take(3)); std::views::take(3)); // print first three elements print(coll2 | std::views::take(3) | std::views::transform([](auto v){ return std::to_string(v) + 's'; })); Output: 0 8 15 47 11 42 1 0 1 8 11 15 42 47 0 Josuttis C++ Filter View @cppcon 2024-09-17 5©2024 by josuttis.com 11 C++ Using a Pipeline to Modify Elements auto vNotEmpty = std::views::filter([] (const auto& rg) { return !rg.empty(); }); std::vector0 码力 | 43 页 | 2.77 MB | 5 月前3
- Regular, RevisitedCompare type ? bool comp(*iter1, *iter2); But what kind of ordering relationship is needed for the elements of the collection ? 🤔 Eg. template
constexpr void std::sort(RandomIt classes determined by equiv() The equivalence relation and its equivalence classes partition the elements of the set, and are totally ordered by <2023 Victor Ciura | @ciura_victor - Regular, Revisited operator= (copy) is shallow (just pointer and size are copied) we could make operator== deep (elements in the span are compared with std::equal()), just like std::string_view wg21.link/p1085 Should 0 码力 | 180 页 | 19.96 MB | 5 月前3 - GraphBLAS: Building a C++ Matrix API for Graph AlgorithmsIteration 108 - Unordered iteration over stored values - Range of size() matrix_entry0 码力 | 172 页 | 7.40 MB | 5 月前3
- A Long Journey of Changing std::sort Implementation at Scaleordering of elements std::sort, std::stable_sort, ranges::sort, etc std::sort(begin, end); std::ranges::sort(cont); 4REMINDERS Sorting is the ordering of elements std::sort 1PROBLEM: TIES std::vector0 码力 | 182 页 | 7.65 MB | 5 月前3
- Back To Basics: Functional Programming in C++different size stdv::transform: apply a function to each element (“map”) stdv::filter: keep only elements that satisfy a predicate Jonathan Müller — @foonathan Back to Basics: Functional Programming in function to each element (“map”) stdv::filter: keep only elements that satisfy a predicate stdv::take_while/drop_while: keep only the first/last elements Jonathan Müller — @foonathan Back to Basics: Functional Derived value stdr::max*/min*: find the maximum/minimum element stdr::count*: count the number of elements satisfying a predicate Jonathan Müller — @foonathan Back to Basics: Functional Programming in C++0 码力 | 178 页 | 918.67 KB | 5 月前3
- Better Code: Contractsunchanged the value of the abstract object d. For example, the function has could re-order the elements of A; this might be an advantage if it is expected that membership of some of the members of the postcondition: returns b = 0 ? a : ⌊a ➗ b⌋ What if sort's spec precisely described which pairs of elements would be compared, and when? 65Strong contracts are simple and relevant 66Strong contracts const vector& second() const; // Returns the number of elements size_t size() const; // Returns true iff there are no elements bool empty() const; // Removes the last element0 码力 | 204 页 | 4.46 MB | 5 月前3
- Back to Basics Almost Always Vector(unsigned size); // Array of given size // Destructor ~DynArray(); // destructs elements and frees dynamic store // Copy and assign DynArray(const DynArray& source); const (unsigned index); const T& operator[] (unsigned index) const; // Low level aaccess to array elements T* base() ; // get address of first element const T* base() const: // Size unsigned std::vector was born! 13What happened in 32 years? 32 member functions! More ways to access elements. Iterators Allocators Modifiers Oh My! 14The Basics 15Creating a std::vector #include0 码力 | 62 页 | 4.86 MB | 5 月前3
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