C learning practice --- use Bubble sorting to return the descending order of a random number column.

C learning practice --- use Bubble sorting to return the descending order of a random number column.

1/* use Bubble sorting to return the descending order of a column of random numbers, and record the time 2 */3 # include <stdio. h> 4 # include <time. h> 5 # include <stdlib. h> 6 # include <windows. h> 7 8 # define LEN 10000 // length of a column 9 # define RANGE 1000 // random number RANGE 0-100010 # define SLEEP_TIME 5000 // waiting time before sorting 11 12 int * get_rand_nums (); 13 int * get_decrease_nums (); 14 15 int main () {16 17 int * p, I, start_time, end_time; 18 19 start_time = time (NULL ); 20 21 p = get_decrease_nums (); 22 printf ("\ nSorted nums: \ n"); 23 for (I = 0; I <LEN; I ++) {24 printf ("% d,", * (p + I); 25} 26 27 end_time = time (NULL); 28 29 printf ("\ nStarting time: % d \ n ", start_time); 30 printf (" Ending time: % d \ n ", end_time); 31 printf (" Total time used: % d S ", end_time-start_time-SLEEP_TIME/1000); 32 printf ("\ a"); 33 return 0; 34} 35 36/* generate LEN random numbers, returns x/37 int * get_rand_nums () {38 39 static int nums [LEN]; 40 41 srand (unsigned) time (NULL); 42 int I; 43 printf ("Generate these nums: \ n"); 44 for (I = 0; I <LEN; I ++) {45 nums [I] = rand () % RANGE; 46 printf ("% d,", nums [I]); 47} 48 49 return nums; 50} 51 52/* use bubble sort to return a descending array */53 int * get_decrease_nums () {54 55 int * arr, I, j, temp; 56 57 arr = get_rand_nums (); 58 printf ("\ nSorting in 5 Senconds ..... "); 59 Sleep (SLEEP_TIME); 60 61 for (I = 0; I <LEN-1; I ++) {62 for (j = 0; j <(LEN-I-1); j ++) {63 if (* (arr + j + 1)> * (arr + j )) {64 temp = * (arr + j); 65 * (arr + j) = * (arr + j + 1); 66 * (arr + j + 1) = temp; 67} 68} 69} 70 71 return arr; 72}