Several common sorting algorithms in C language

1, Bubble sorting method: If there are n number, 22 adjacent to compare, will sink the most value into the last position, to do N-1 wheel comparison,

The first round to compare N-1 times, the 2nd round as long as the comparison n-1-1 times, because the first time has already sunk the most value into the last position, so

Does not need to be compared once, that is, each round is reduced one time, so the 2nd for loop J < n-1; The following code is sorted in ascending order

1 voidBubble_sort (int*num,intN)2 {3     intnum_temp;4      for(intI=0; i<n; i++)  5          for(intj=0; j<n-i;j++)6         {7             if(Num[j] > num[j+1])8             {9Num_temp =Num[j];TenNUM[J] = num[j+1]; Onenum[j+1] =num_temp; A             } -         } -}

2. Select sort: Each cycle (that is, the 2nd for loop) finds only the position of the minimum value, but does not exchange the data.

After the end of the round, judging whether the minimum mark is the same as the original hypothesis, if not the same, the other position is smaller (or larger),

When the data is swapped, the data is exchanged only once per round cycle. And in the bubble sort, the 2nd loop, just find the bad

The value will be exchanged, and multiple exchanges will be performed in a round loop. Bubble Sorting is therefore more time-consuming than selecting a sort. The following code is sorted in descending order

1 voidSelect_sort (int*num,intN)2 {3     intk_min;4     intNum_temp =0;5 6      for(intI=0; i<n-1; i++)  7     {8K_min = i;//assuming the first minimum9          for(intj=i+1; j<n; J + +)Ten         { One             if(Num[k_min] <Num[j]) A             { -K_min =J; -             } the         } -  -         if(K_min! = i)//data Exchange -         { +Num_temp =Num[i]; -Num[i] =Num[k_min]; +Num[k_min] =num_temp; A         } at     } -}

Overall code:

1#include <iostream.h>2 #defineN 103 4 voidBubble_sort (int*num,intN)5 {6     intnum_temp;7      for(intI=0; i<n; i++)  8          for(intj=0; j<n-i;j++)9         {Ten             if(Num[j] > num[j+1]) One             { ANum_temp =Num[j]; -NUM[J] = num[j+1]; -num[j+1] =num_temp; the             } -         } - } -  + voidSelect_sort (int*num,intN) - { +     intk_min; A     intNum_temp =0; at  -      for(intI=0; i<n-1; i++)   -     { -K_min = i;//assuming the first minimum -          for(intj=i+1; j<n; J + +) -         { in             if(Num[k_min] <Num[j]) -             { toK_min =J; +             } -         } the  *         if(K_min! = i)//data Exchange $         {Panax NotoginsengNum_temp =Num[i]; -Num[i] =Num[k_min]; theNum[k_min] =num_temp; +         } A     } the } +  - intMain () $ { $     intNum[n] = { the,6, A,9, the,8, -, -,1,3}; -  - //Bubble_sort (num,n); the Select_sort (num,n); - Wuyi      for(intI=0; i<n; i++) the     { -cout<<num[i]<<Endl; Wu     } -  About     return 0; $}

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Several common sorting algorithms in C language