Data structure and algorithm analysis--c language description

P1.1 Select the problem, select the number of K, and draw N for the different values of the run time, K=N/2

Graduation 2.5, rewrite sort, feel good. The code uses a bubbling sort, and the library functions clock calculates the approximate run time.

1 //P1_1.cpp:Defines the entry point for the console application.2 //3 4#include"stdafx.h"5#include <malloc.h>6#include <stdlib.h>7#include <time.h>8 9 voidSwapint& A,int&b);Ten  One intMainintargcChar*argv[]) A { -  -     intN =40000; the     intK = n/2; -     inti,j; -  -     //Dynamic Arrays +     int*dynarr = (int*)mallocNsizeof(int)); -     //generating a random array + Srand ((unsigned) time (NULL)); A      //printf ("%d%c", Rand (), ' \ t '); at       for(i=0; i<n;i++) -      { -Dynarr[i] = rand ()% -; -          //printf ("%d%c", dynarr[i], ' \ t '); -      } -  in  -     intBeginTime = Clock ();//Timing Starts to  +     //Bubble Sort -     inttemp =0; the      for(i=0; i<n;i++) *          for(j=0; j<n;j++) $         {Panax Notoginseng             if(Dynarr[i]>dynarr[j]) {//left > right, swap - swap (dynarr[i],dynarr[j]); the             }     +}//The first layer ends, the maximum number is at the right A  the     intEndTime = Clock ();//End of timing +     intRunningtime = Endtime-begintime;//the calculated units are milliseconds . -  $  $  -      for(i=0; i<n;i++){ -     //Dynarr[i] = rand ()%100; the          //printf ("%d%c", dynarr[i], ' \ t '); -      }Wuyi      the     CharStr1[] ="number of K-Large numbers:"; -     CharStr2[] ="elapsed Time (milliseconds):"; Wuprintf"\n%d%s%d\t", N,str1,dynarr[k]); -printf"\n%s%d\n", str2,runningtime); About  $  -     return 0; - } -  A voidSwapint& Left,int&Right ) { +     inttemp; thetemp =Left ; -left =Right ; $right =temp; the}

Change the N value to test the elapsed time of different sample values.

If the data is a student's examination result of one subject, percentile. n indicates the number of students.

N Time (MS)
00
501
1005
50049
1000101
5000272

N (million) time (MS)
1281
21109
32506
44384
56764
69747
713296
817421
922078
1027307

Use this site to plot graphs:

Feeling is an increment. In fact, this is an illusion ... Look at these two small graphs:

The number of people is normal increment, but time is not increment, time cost is rising rapidly.

Data structure and algorithm analysis--c language description