Use the following problems to test your programming prowess based on arrays, collections, and data structures. I strongly encourage you to give each problem a try before you turn to the solutions and download the example programs:

99. Sorting an array: Write several programs that exemplify different sorting algorithms for arrays. Also, write a program for shuffling arrays.
100. Finding an element in an array: Write several programs that exemplify how to find the given element (primitive and object) in a given array. Find the index and/or simply check whether the value is in the array.
101. Checking whether two arrays are equal or mismatches: Write a program that checks whether the two given arrays are equals or whether there is a mismatch.
102. Comparing two arrays lexicographically: Write a program that compares the given arrays lexicographically.

103. Creating a stream from an array: Write a program that creates a stream from the given array.
104. Minimum, maximum, and average of an array: Write a program that computes the maximum, minimum, and average of the given array.
105. Reversing an array: Write a program that reverses the given array.
106. Filling and setting an array: Write several examples for filling up an array and setting all elements based on a generator function to compute each element.
107. Next Greater Element (NGE): Write a program that returns the NGE for each element of an array.
108. Changing array size: Write a program that adds an element to an array by increasing its size by one. In addition, write a program that increases the size of an array with the given length.
109. Creating unmodifiable/immutable collections: Write several examples that create unmodifiable and immutable collections.
110. Mapping a default value: Write a program that gets a value from Map or a default value.
111. Computing whether absent/present in a Map: Write a program that computes the value of an absent key or a new value of a present key.
112. Removal from a Map: Write a program that removes from a Map by means of the given key.
113. Replacing entries from a Map: Write a program that replaces the given entries from a Map.
114. Comparing two maps: Write a program that compares two maps.
115. Merging two maps: Write a program that merges two given maps.
116. Copying HashMap: Write a program that performs a shallow and deep copy of HashMap.
117. Sorting a Map: Write a program that sorts a Map.
118. Removing all elements of a collection that match a predicate: Write a program that removes all elements of a collection that match the given predicate.
119. Converting a collection into an array: Write a program that converts a collection into an array.
120. Filtering a collection by List: Write several solutions for filtering a collection by a List. Reveal the best way of doing this.
121. Replacing elements of a List: Write a program that replaces each element of a List with the result of applying a given operator to it.
122. Thread-safe collections, stacks, and queues: Write several programs that exemplify the usage of Java thread-safe collections.
123. Breadth-first search (BFS): Write a program that implements the BFS algorithm.
124. Trie: Write a program that implements a Trie data structure.
125. Tuple: Write a program that implements a Tuple data structure.
126. Union Find: Write a program that implements the Union Find algorithm.
127. Fenwick Tree or Binary Indexed Tree: Write a program that implements the Fenwick Tree algorithm.
128. Bloom filter: Write a program that implements the Bloom filter algorithm.