[easy] 3318. Find X-Sum of All K-Long Subarrays I

Author: joffilyfe

3318.py

@@ -0,0 +1,44 @@
+from typing import List
+
+class Solution:
+    def findXSum(self, nums: List[int], k: int, x: int) -> List[int]:
+        numbers = {}
+        size = len(nums) - k + 1
+        answer = [-1] * size
+        j = 0
+
+        for i, number in enumerate(nums):
+            numbers[number] = numbers.get(number, 0) + 1
+
+            # building while iterating over the list
+            # in every loop we need to check if the window is full (k)
+            # when the window is full then we extract the first x-sum:
+            #
+            # filter the numbers that have value (ocurrencies) > x
+            # if occurencies are equal then keep only the higher key
+            # then sum result of previous operation
+            # then add to the res array
+
+            if i - k + 1 >= 0:
+                # this is the logic required by the problem. We need to get the top
+                # elements sorted by the qty then if they draw the bigger number will
+                # be selected
+                sums = sorted([(v, key) for key, v in numbers.items()], reverse=True)
+                # then keep only the X top elements
+                answer[j] = sum([pair[0] * pair[1] for pair in sums[:x]])
+                j += 1
+
+                # need to reduce the quantity of the number i - k + 1 positions ago
+                numbers[nums[i - k + 1]] -= 1
+
+        return answer
+
+nums = [1,1,2,2,3,4,2,3]
+k = 6
+x = 2
+
+nums = [3,8,7,8,7,5]
+k = 2
+x = 2
+
+print(Solution().findXSum(nums, k, x))

README.md

@@ -68,6 +68,7 @@
 | 2848.py        |                            |                                                                                        |
 | 2913.py        |                            |                                                                                        |
 | 2932.py        |                            |                                                                                        |
+| 3318.py        | Array / Sliding Window     | <https://leetcode.com/problems/find-x-sum-of-all-k-long-subarrays-i>                   |
 | 414.py         |                            |                                                                                        |
 | 496.py         |                            |                                                                                        |
 | 56.py          |                            |                                                                                        |