Quicksort is a recursive algorithm.
Given an array and indices to the lower and upper bounds of a subset within the array, divide the subset into two subsets around a pivot value then recursively apply the algorithm to each of these subsets until a subset has fewer than 2 elements.
The algorithm begins by checking the size of the given subset. If there are fewer than 2 elements then the subset is sorted. This represents the end condition for this instance of the algorithm since a subset of 0 or 1 elements can always be regarded as being sorted.
If the set has 2 or more elements, however, a pivot element is selected . the pivot is typically the mode of the first, last and middle elements. The pivot is then swapped with the last element so it's out of the way.
Two indices are then instantiated, left and right, one referring to the first element (the lower bound), the other referring to the penultimate element (we ignore the pivot at the end for now).
While the left index is less than the right index, repeat:
1. While left is less than right and the value referred to by left is less than the pivot, increment left. (In other words, search for the first value from the left but no further than the right that is not less than the pivot).
2. While right is greater than left and the value referred to by right is not less than the pivot, decrement right. (In other words, search for the first value from the right but no further than the left index that is less than the pivot).
3. If the left and right indices are not equal, swap the values at those indices.
When the indexes are the same, or left crosses right, the loop ends.
Swap the value at the left index with the last element (the pivot).
At this point, the pivot is now in place and all values less than the pivot are to its left, with all others to its right. The values on either side are not yet sorted, thus we recursively invoke the same algorithm to sort each of these two subsets (excluding the pivot, of course).
Since the set is divided into two smaller subsets upon each invocation of the algorithm, each recursion takes less time because there are fewer elements to divide. The recursions effectively form a binary tree with one recursion per node. Some nodes will terminate earlier than others so the tree will probably be unbalanced. But since the sorting is done in-place, each recursion will unwind automatically leaving behind a sorted subset within the set. When the initial instance of the algorithm terminates, the entire set is sorted.
Yes, that's how quick-sort works.
Quick Sort
quick sort
Because the quick sort can be used for large lists but selection not. selection sort is used to find the minimum element ,but quick choose element called pivot and move all smaller nums before it & larger after it.
Comolexity Not efficent big data
Yes, that's how quick-sort works.
Quick Sort
Yes, Quick Sort is an in-place sorting algorithm.
When you want to sort an array.
Quick sort is more efficient for large datasets compared to selection sort.
Although quick sort has a worst case time complexity of O(n^2), but for sorting a large amount of numbers, quick sort is very efficient because of the concept of locality of reference.
quick sort is a divide and conquer method , it is not dynamic programming
quick sort
quick sort
it has less complexity
Because the quick sort can be used for large lists but selection not. selection sort is used to find the minimum element ,but quick choose element called pivot and move all smaller nums before it & larger after it.
Comolexity Not efficent big data