Tony Hoare invented QuickSort in his 1961 paper, QuickSort. At the time of its publication, the best comparison-based sorting algorithm was merge sort. Merge sort divides an unordered array into two equally sized subarrays, sorts each subarray, and then merge the two subarrays to produce a sorted array. Merge sort is …

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Modern CPUs operate significantly faster than memories. For instance, a 4.5 GHz x64 CPU operates 30 times faster than a 6000 MHz DDR5 memory of CAS Latency 36. Adding latencies incurred by the bus and memory coherency protocols, CPU access to memory could be 100 times slower than CPU access to registers. To mitigate …

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Problem Given an integer array A, in one step, remove all elements A[i] where A[i-1] > A[i]. Return the number of steps performed until A becomes a non-decreasing array. See examples at LeetCode 2289. Solution The naive approach executes steps one by one. Store integers in a Linked List. At each step, find all …

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