Topic: array-problem / Level: beginner

• 101. Find the average of the elements in each row of a 2D array.
• 102. Check if a 2D array is an identity matrix (diagonal elements are 1 and all other elements are 0).
• 103. Find the number of rows and columns in a 2D array that contain only zeros.
• 104. Check if an array of integers forms an arithmetic progression.
• 105. Check if an array of integers forms a geometric progression.
• 106. Find the sum of elements at odd indices in an array.
• 107. Find the sum of elements at even indices in an array.
• 108. Check if a given matrix is a lower triangular matrix.
• 109. Check if a given matrix is an upper triangular matrix.
• 110. Find the number of positive and negative numbers in an array.
• 111. Count the number of perfect squares in an array.
• 112. Check if a given matrix is diagonal (all non-diagonal elements are zero).
• 113. Find the sum of the first half of an array.
• 114. Find the sum of the second half of an array.
• 115. Convert an array into its mirror image (reverse the array).
• 116. Find the sum of elements between the minimum and maximum element in an array.
• 117. Check if a 2D matrix is symmetric about its main diagonal.
• 118. Find the row with the minimum sum in a 2D array.
• 119. Find the row with the maximum product in a 2D array.
• 120. Count how many rows contain negative numbers in a 2D array.
• 121. Count how many columns contain positive numbers in a 2D array.
• 122. Check if a given 2D matrix is sparse (more than half of its elements are zero).
• 123. Find the maximum element in each diagonal of a 2D array.
• 124. Find the sum of the boundary elements of a 2D matrix.
• 125. Check if an array is monotonic (either entirely non-increasing or non-decreasing).
• 126. Count the number of prime numbers in an array.
• 127. Find the greatest common divisor (GCD) of all elements in an array.
• 128. Find the least common multiple (LCM) of all elements in an array.
• 129. Find the sum of elements in an array until a negative number is encountered.
• 130. Replace all even numbers in an array with their square.
• 131. Replace all odd numbers in an array with their cube.
• 132. Find the average of all prime numbers in an array.
• 133. Sort an array of integers using selection sort.
• 134. Find the row in a 2D matrix with the largest number of even elements.
• 135. Find the column in a 2D matrix with the largest number of odd elements.
• 136. Find the smallest element in an array that is greater than the average of the array.
• 137. Sort the elements of a 2D matrix by row.
• 138. Sort the elements of a 2D matrix by column.
• 139. Check if the elements of an array are in strictly increasing order.
• 140. Check if the elements of an array are in strictly decreasing order.
• 141. Find the index of the first occurrence of a given element in an array.
• 142. Find the index of the last occurrence of a given element in an array.
• 143. Check if an array contains only positive integers.
• 144. Find the sum of elements in an array that are greater than the given threshold.
• 145. Count the number of elements in an array that are divisible by both 2 and 3.
• 146. Find the smallest prime number in an array.
• 147. Find the largest composite number in an array.
• 148. Reverse the rows of a 2D array.
• 149. Reverse the columns of a 2D array.
• 150. Find the product of all elements in an array excluding zeros.

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