✨ hashmap and linear search

Author: fz3hra

HashMap/dart/count_occurance_of_a_word/.gitignore

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+# Files and directories created by pub.
+.dart_tool/
+.packages
+
+# Conventional directory for build output.
+build/

HashMap/dart/count_occurance_of_a_word/CHANGELOG.md

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+## 1.0.0
+
+- Initial version.

HashMap/dart/count_occurance_of_a_word/README.md

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+Big Time complexity - O(1)
+Space Complexity - O(n)
+
+[Algorithm Explanation](https://stackoverflow.com/questions/63369213/is-the-extra-space-complexity-of-a-function-that-counts-letter-occurrences-o1)
+
+[Algorithm Explanation](https://stackoverflow.com/questions/27334494/space-complexity-of-hashmap-when-iterating-over-an-array-in-linear-time)

HashMap/dart/count_occurance_of_a_word/analysis_options.yaml

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+# This file configures the static analysis results for your project (errors,
+# warnings, and lints).
+#
+# This enables the 'recommended' set of lints from `package:lints`.
+# This set helps identify many issues that may lead to problems when running
+# or consuming Dart code, and enforces writing Dart using a single, idiomatic
+# style and format.
+#
+# If you want a smaller set of lints you can change this to specify
+# 'package:lints/core.yaml'. These are just the most critical lints
+# (the recommended set includes the core lints).
+# The core lints are also what is used by pub.dev for scoring packages.
+
+include: package:lints/recommended.yaml
+
+# Uncomment the following section to specify additional rules.
+
+# linter:
+#   rules:
+#     - camel_case_types
+
+# analyzer:
+#   exclude:
+#     - path/to/excluded/files/**
+
+# For more information about the core and recommended set of lints, see
+# https://dart.dev/go/core-lints
+
+# For additional information about configuring this file, see
+# https://dart.dev/guides/language/analysis-options

HashMap/dart/count_occurance_of_a_word/bin/count_occurance_of_a_word.dart

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+import 'package:count_occurance_of_a_word/count_occurance_of_a_word.dart'
+    as hashmap;
+
+void main(List<String> arguments) {
+  String sentence = "The cat ate the dog";
+  Map<String, int> results = hashmap.hashmap(sentence);
+  print("results $results");
+}

HashMap/dart/count_occurance_of_a_word/lib/count_occurance_of_a_word.dart

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+import 'dart:collection';
+
+/***
+ * The purpose is to use hashmap and count the number of times a word appears in a phrase also called word frequency
+ * for example:
+ * 1. hello world::
+ * hello: 1
+ * world: 1
+ * 2. the cat ate the dog
+ * the: 2
+ * cat: 1
+ * ate: 1
+ * dog: 1
+ * 
+ * Using HashMap to store the words and count the numbers
+ * first we need to tokenize the phrase
+ * 
+ * method should take the sentence and return a hashmap
+ */
+
+Map<String, int> hashmap(String sentence) {
+  final Map<String, int> map = HashMap();
+  List<String> tokenize = sentence.split(" ");
+  for (int i = 0; i < tokenize.length; i++) {
+    String word = tokenize[i].toLowerCase();
+    print("word $word");
+    if (map.containsKey(word)) {
+      int count = map[tokenize[i]] ?? 0;
+      var data = <String, int>{word: count + 1};
+      map.addAll(data);
+    } else {
+      var data = <String, int>{word: 1};
+      map.addAll(data);
+    }
+  }
+  return map;
+}