[Algorithm] various sorting algorithms implemented in C ++

We usually refer to sorting algorithm often refers to the internal sorting algorithm that sorts the data recorded in the memory.

　　Sorting algorithms can be roughly divided into two types:

　　　　One is the comparison sort , the time complexity of O (nlogn) ~ O (n ^ 2), are: bubble sort , selection sort , insertion sort , merge sort , heap sort , quicksort like.

　　　　Another is the non-sort comparison , the time complexity can be achieved O (n), are: counting sort , radix sort , bucket sort the like.

The following table shows the performance comparison of common sorting algorithm:

 

For convenience of the following description, the following algorithms are all sort object scrambled array int a [n];

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1. Bubble Sort (BubbleSort)

Idea: to compare two adjacent elements, so each round of relatively complete current maximum (small) element will be moved to the tail, so to repeat n wheel, you can achieve the sort.

achieve:

 1 void bubbleSort(int a[],int begin,int end)
 2 {
 3   for(int i = begin;i<end;i++)
 4   {
 5     for(int j = i+1;j<end;j++)
 6     {
 7       if(a[i]>a[j])
 8       {
 9         std::swap(a[i],a[j]);
10       }
11     }
12   }
13 }

FIG particular ordering process:

 

to sum up:

Simple sorting algorithm, stability, since the two-cycle so complexity is O (n- ² ). (But think of when asked about that year for the first time looking for work, the results come out as expected no answer, really made me feel embarrassed algorithm.)

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Reference article: https://www.cnblogs.com/eniac12/p/5329396.html#s1