使用C語言內建的Sort

#include <stdio.h>

#include <stdlib.h>

#define ARR_LEN 5

typedef struct

{

int m_i;

char m_c;

} my_struct;

int compare_for_int(const void* a, const void* b)

{

return (*(int*)a > *(int*)b);

}

// we compare the larger structure by the memeber m_i

int compare_for_struct(const void* a, const void* b)

{

return ((my_struct*)a)->m_i > ((my_struct*)b)->m_i;

}

int main (int argc, char** argv)

{

int i;

int arr[ARR_LEN] = {2,4,1,8,10};

my_struct* arr_struct;

srand(time(NULL));

// demo for int

puts("orig data:");

for (i=0 ; i<ARR_LEN ; ++i)

printf("%d, ", arr[i]);

puts("");

qsort((void*)arr, ARR_LEN, sizeof(int), compare_for_int);

puts("sorted data:");

for (i=0 ; i<ARR_LEN ; ++i)

printf("%d, ", arr[i]);

puts("");

// demo for structures 

arr_struct = (my_struct*)malloc(sizeof(my_struct)*ARR_LEN);

// init random data 

for (i=0 ; i<ARR_LEN ; ++i)

arr_struct[i].m_i = rand()%100+1;

puts("orig struct data:");

for (i=0 ; i<ARR_LEN ; ++i)

printf("%d, ", arr_struct[i].m_i);

puts("");

qsort((void*)arr_struct, ARR_LEN, sizeof(my_struct), compare_for_struct);

puts("sorted struct data:");

for (i=0 ; i<ARR_LEN ; ++i)

printf("%d, ", arr_struct[i].m_i);

puts("");

free(arr_struct);

return 0;

}