Contest Records Problem Rating Notes 3478. Choose K Elements With Maximum Sum 1753 (index, value) mapping + sorting https://leetcode.com/problems/minimum-absolute-difference-in-sliding-submatrix/description/ https://leetcode.com/problems/fill-a-special-grid/description/ Data Structure Problem Rating Notes https://leetcode.com/problems/find-mirror-score-of-a-string/description/ 1578