Civil Rights
Movements, leaders, victories and the continuing fight for equality.
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Explore the people, places, events, achievements, struggles and stories that shaped our journey.
Movements, leaders, victories and the continuing fight for equality.
Innovation, patents, science, technology and world-changing contributions.
Pioneers, champions, Negro Leagues, records, activism and excellence.
Meet the people whose lives, choices and achievements shaped the journey.
Black towns, communities, institutions and places where history happened.
Moments that changed communities, movements, institutions and the nation.
In 1968 Shirley Chisholm became the first Black woman elected to the United States Congress. In 1972 she launched a campaign for the Democratic presidential nomination, breaking another political barrier.
MORE →Reflects the personal views, recollections, and perspective of the author, Mike Davis.
This is a personal recollection on the Move fire on May 13, 1985
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In computer science, a multimap (sometimes also multihash, multidict or multidictionary) is a generalization of a map or associative array abstract data type in which more than one value may be associated with and returned for a given key. Both map and multimap are particular cases of containers (for example, see C++ Standard Template Library containers). Often the multimap is implemented as a map with lists or sets as the map values.
C++'s Standard Template Library provides the multimap container for the sorted multimap using a self-balancing binary search tree,[1] and SGI's STL extension provides the hash_multimap container, which implements a multimap using a hash table.[2]
As of C++11, the Standard Template Library provides the unordered_multimap for the unordered multimap.[3]
Quiver provides a Multimap for Dart.[4]
Apache Commons Collections provides a MultiMap interface for Java.[5] It also provides a MultiValueMap implementing class that makes a MultiMap out of a Map object and a type of Collection.[6]
Google Guava provides a Multimap interface and implementations of it.[7]
Kotlin does not have explicit support for multimaps,[8] but can implement them using Maps with containers[9] for the value type. E.g. a Map<User, List<Book>> can associate each User with a list of Books.
Python provides a collections.defaultdict class that can be used to create a multimap. The user can instantiate the class as collections.defaultdict(list).
OCaml's standard library module Hashtbl implements a hash table where it's possible to store multiple values for a key.
The Scala programming language's API also provides Multimap and implementations.[10]
Source: Wikipedia. Article content is retrieved live through the MediaWiki API.
In computer science, a multimap (sometimes also multihash, multidict or multidictionary) is a generalization of a map or associative array abstract data type in which more than one value may be associated with and returned for a given key. Both map and multimap are particular cases of containers (for example, see C++ Standard Template Library containers). Often the multimap is implemented as a map with lists or sets as the map values.
Multimap.com was a provider of mapping and location-based services. Founded around 1997 and based in London, it was acquired by Microsoft in 2007 for $50 million. It was then merged into Bing Maps. It offered street maps and door-to-door travel directions on a public web site. Other offerings included aerial photography, local information, and business services. Services were also offered through its partners, including accommodation, restaurant and train-ticket booking. It also sold historic and aerial photograph prints. Multimap offered discrete panning by clicking links, a form of user interaction later displaced by continuous panning 'slippy' maps. The Geo microformat was used to provide a Wikipedia map overlay generated from the official database download. This was used to browse geotagged articles.
In C++, sequence containers or sequence collections refer to a group of container class templates in the standard library that implement storage of data elements. Being templates, they can be used to store arbitrary elements, such as integers or custom classes. One common property of all sequential containers is that the elements can be accessed sequentially. Like all other standard library components, they reside in namespace std. The following containers are defined in the current revision of the C++ standard: std::array implements a compile-time non-resizable array. std::bitset implements a compile-time bit set. std::vector implements an array with fast random access and an ability to automatically resize when appending elements. std::inplace_vector implements a resizable array with contiguous in-place storage. std::deque implements a double-ended queue with comparatively fast random access. std::list implements a doubly linked list. std::forward_list implements a singly linked list. std::hive implements an object pool. Each of these containers implements different algorithms for data storage, which means that they have different speed guarantees for different operations. There are also versions of these collections in namespace std::pmr (for polymorphic memory resources). These versions specify the optional template parameter Allocator as std::pmr::polymorphic_allocator. C++ further defines container adapters that wrap a sequence container: std::stack implements a stack with deque as the default underlying container. std::queue implements a queue with deque as the default underlying container. std::priority_queue implements a priority queue (by default max heap) with vector as the default underlying container. std::flat_set implements a "flat set" (stores a sorted set of unique keys) with vector as the default underlying container. std::flat_map implements a "flat map" (stores a sorted set of unique key-value pairs) with vector as the default underlying containers. std::flat_multiset implements a "flat multi-set" (stores a sorted set of keys) with vector as the default underlying container. std::flat_multimap implements a "flat multi-map" (stores a sorted set of key-value pairs) with vector as the default underlying containers. The "flat" collections (std::flat_set, std::flat_map, std::flat_multiset, and std::flat_multimap) use std::vector as the underlying container, unlike their "non-flat" equivalents (std::set, std::map, std::multiset, and std::multimap), which store data as red–black trees (hence being "flat"). View container types represent views over non-owning arrays of elements: std::span implements a non-owning view over a contiguous sequence of objects. std::mdspan implements a non-owning view over a multi-dimensional array. Since each of the containers needs to be able to copy its elements in order to function properly, the type of the elements must fulfill CopyConstructible and Assignable requirements. For a given container, all elements must belong to the same type. For instance, one cannot store data in the form of both char and int within the same container instance.
In C++, associative containers are class templates in the standard library that maintain their elements in an order determined by their keys and provide key-based lookup. They reside in namespace std and are parameterized by a key type, a comparison function, and an allocator; maps also have a mapped-value type. The standard specifies four basic associative containers: std::set std::map std::multiset std::multimap set and map store at most one element for each equivalent key, whereas multiset and multimap permit multiple elements with equivalent keys. Maps store a mapped value with each key; sets store keys alone. Since C++17, alias templates for these containers have also been provided in namespace std::pmr; they use std::pmr::polymorphic_allocator as the allocator type. std::set and std::multiset are declared in header , while std::map and std::multimap are declared in header . Unlike the unordered associative containers, which organize elements into hash-table buckets and do not specify an overall iteration order, associative containers traverse their elements in non-descending key order. The two groups also provide different complexity guarantees. std::map and std::set are commonly implemented as red-black trees, although the standard does not require that representation. Comparable ordered map and set types include java.util.TreeMap and java.util.TreeSet in Java, System.Collections.Generic.SortedDictionary and System.Collections.Generic.SortedSet in .NET, and std::collections::BTreeMap and std::collections::BTreeSet in Rust.
Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.
MORE →Shirley Chisholm, elected in 1968.
