Topic: array-problem / Level: beginner

• 151. Check if an array contains only unique elements.
• 152. Find the sum of the elements in a 2D array.
• 153. Find the largest element in each row of a 2D array.
• 154. Find the largest element in each column of a 2D array.
• 155. Calculate the sum of the boundary elements in a 2D array.
• 156. Find the sum of the even elements in an array.
• 157. Find the sum of the odd elements in an array.
• 158. Find the middle element of an array.
• 159. Reverse only the first half of an array.
• 160. Reverse only the second half of an array.
• 161. Check if an array is a subset of another array.
• 162. Find the number of subarrays in an array whose sum equals zero.
• 163. Calculate the mean, median, and mode of the elements in an array.
• 164. Find the first repeated element in an array.
• 165. Find the longest contiguous subsequence where all elements are the same.
• 166. Rotate an array in-place by one position to the left.
• 167. Rotate an array in-place by one position to the right.
• 168. Check if an array has at least one duplicate element.
• 169. Sort the first half of an array in ascending order and the second half in descending order.
• 170. Split an array into k parts and find the sum of each part.
• 171. Merge two arrays such that the resulting array has no duplicates.
• 172. Find the most frequent odd element in an array.
• 173. Find the most frequent even element in an array.
• 174. Count the number of elements in an array that are divisible by a given number.
• 175. Calculate the square root of each element in an array.
• 176. Find the element that appears exactly twice in an array.
• 177. Check if an array contains any negative numbers.
• 178. Find the sum of the absolute values of all elements in an array.
• 179. Replace all elements greater than a given value x with x in an array.
• 180. Find the sum of elements at the corners of a 2D matrix.
• 181. Check if a given matrix is a unit matrix (all diagonal elements are 1 and all off-diagonal elements are 0).
• 182. Find the sum of each row in a 2D array.
• 183. Find the product of the diagonal elements of a 2D matrix.
• 184. Find the sum of elements in the first column of a 2D matrix.
• 185. Find the largest element in the first row of a 2D matrix.
• 186. Count how many elements in an array are prime numbers.
• 187. Replace all negative elements in an array with their absolute value.
• 188. Check if an array contains both positive and negative numbers.
• 189. Find the index of the smallest element in an array.
• 190. Find the index of the largest element in an array.
• 191. Find the number of elements in an array that are divisible by a given number k.
• 192. Check if the sum of all elements in an array is even.
• 193. Find the product of all positive elements in an array.
• 194. Find the product of all negative elements in an array.
• 195. Find the sum of the largest and smallest elements in an array.
• 196. Sort an array of integers using the heap sort algorithm.
• 197. Find the minimum difference between any two elements in an array.
• 198. Find the sum of squares of all elements in an array.
• 199. Check if an array is a rotation of another array.
• 200. Find the maximum element in an array that is smaller than a given value x.

• More Levels

• Intermediate
• Advanced