Selection sorting

Selection sorting

• 1.
  A SEMINAR ON SELECTION SORT PresentedTo- Mr. K.S.Bumrah Asst. Proff. Deptt. Of C.S.E Presented By- Kunal kesharwani
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  Contents  Description.  SortAlgorithm.  Example.  Analysis.  Advantages of Sorting Algorithms.  Disadvantages of Sorting Algorithms.
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  Description  This sortingalgorithm is an in-place comparison- based algorithm .  in which the list is divided into two parts, the sorted part at the left end and the unsorted part at the right end.  Initially, the sorted part is empty and the unsorted part is the entire list.
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  Description Contd.  Thesmallest element is selected from the unsorted array and swapped with the leftmost element, and that element becomes a part of the sorted array.  This process continues moving unsorted array boundary by one element to the right  each time selecting an item according to its ordering and placing it in the correct position in the sequence.
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  The Selection SortAlgorithm  For each index position i  Find the smallest data value in the array from positions i through length - 1 , where length is the number of data values stored.  Exchange (swap) the smallest value with the value at position i.
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  Algorithm  Step 1− Set MIN to location 0  Step 2 − Search the minimum element in the list  Step 3 − Swap with value at location MIN  Step 4 − Increment MIN to point to next element  Step 5 − Repeat until list is sorted
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  Example  Unsorted list: 1st iteration:  Smallest = 5  2 < 5, smallest = 2  1 < 2, smallest = 1  4 > 1, smallest = 1  3 > 1, smallest = 1 Swap 5 and 1 5 2 1 4 3 1 2 5 4 3
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  Example contd.  2nditeration:  Smallest = 2  2 < 5, smallest = 2  2 < 4, smallest = 2  2 < 3, smallest = 2  No swap 1 2 5 4 3
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  Example contd.  3rditeration:  Smallest = 5  4 < 5, smallest = 4  3 < 4, smallest = 3  Swap 5 and 3 1 2 3 4 5
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  Example contd.  4thiteration:  Smallest = 4  4 < 5, smallest = 4  No swap  Finally, the sorted list is 1 2 3 4 5 1 2 3 4 5
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  Selection Sort: Analysis Complexity: Best case performanceО(n2)  Average case performanceО(n2)  Worst case performanceО(n2)
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  Advantages & Disadvantages AdvantagesDisadvantages  The main advantage of the selection sort is that it performs well on a small list.  no additional temporary storage is required.  The primary disadvantage of the selection sort is its poor efficiency when dealing with a huge list of items.  the selection sort requires n- squared number of steps for sorting n elements.