Sorting algorithm 6--Selection sort--Simple selection sorting

Simple selection sorting

Simple selection sort belongs to the selection sort, the idea of sorting is: Each trip from the records to be sorted to select the smallest record of the keyword, in order after the sequence of records sorted, until all the rows are complete.

1. Simple selection of the sorting method is to find the maximum value per cycle, the end of the loop to adjust the maximum value to the appropriate position, the number of exchanges less.

Each time you find the smallest element in the current unordered queue with the first swap location, select the second small one with the second swap location
Original queue: 3 5 6 2 4 1 (minimum element 1 and 3 interchange)
First step: 1 5 6 2 4 3 (current minimum element 2 and 5 interchange)
Step Two: 1 2 6 5 4 3 (Current minimum element 3 and 6 interchange)
Step Three: 1 2 3 5 4 6 (Current minimum element 4 and 5 interchange)
Fourth Step: 1 2 3 4 5 6
Fifth Step: 1 2 3 4 5 6
Sixth step: 1 2 3 4 5 6

2. Complexity of Time

Best case (positive order) does not move

Worst case (reverse order) Move 3 (n-1) times

Average Time complexity O (n*n)

Space complexity O (1)

For detailed analysis of time complexity, please refer to: http://www.cnblogs.com/zhangxue521/p/6748085.html

3. Algorithm Features

① Stable Sorting

② can be used for chained storage structures

③ Mobile records are less frequent, and when each record occupies more space, this method is faster than the direct insert sort

Java implementations:

1  Packageusually used;2 3 ImportJava.util.Scanner;4 5  Public class_2 Simple selection Sort {6      Public Static voidMain (string[] args) {7         intA[] =New int[6];8Scanner Scanner =NewScanner (system.in);9           for(inti = 0; i < a.length; i++) {TenA[i] =scanner.nextint (); One         } A               for(inti = 0; i < a.length; i++) { -                 intMin =i; - //loops through the smallest number in the current queue and assigns the Min flag to it the                  for(intJ =i+1; J < A.length; J + +) { -                     if(a[j]<A[min]) { -Min =J; -                     } +                 } -                 //Exchange minimum value to the front of the current unordered queue +                     if(min!=i) { A                         inttemp =A[i]; atA[i] =A[min]; -A[min] =temp; -                     } -                  for(intm:a) { -System.out.print (m+ ""); -                 } in System.out.println (); -             } to     } +}

JS implementation:

1 functionJiandansort (a) {2     vari,j,temp,min;3      for(i=0;i<a.length;i++) {4Min =i;5         //Loop to find the minimum value of the current queue6          for(j = i+1;j<a.length;j++) {7             if(a[j]<A[min])8Min =J;9         }Ten         //swap the minimum value to the front of the current unordered queue One         if(min!=i) { Atemp =A[i]; -A[i] =A[min]; -A[min] =temp; the         } -     } - } - varA =NewArray (7,2,6,5,1,4,3); + Jiandansort (a); -document.write ("_6 Simple selection Sort:" +a + "<br/>");

Sorting algorithm 6--Selection sort--Simple selection sorting