C语言 实现归并排序算法

// Completed on 2014.10.11 17:20
// Language: C99
//
// 版权所有（C）codingwu  (mail: oskernel@126.com) 
// 博客地址：http://www.cnblogs.com/archimedes/
#include<stdio.h>
#include<stdlib.h>void merge_sort(int *list, const int first, const int last)
{
  int len= last-first+1; 
  int left_min,left_max;  //左半区域边界 
  int right_min,right_max; //右半区域边界 
  int index;
  int i;
  int *tmp;
  tmp = (int *)malloc(sizeof(int)*len);
  if( tmp == NULL || len <= 0 )
    return;
  
  for( i = 1; i < len; i *= 2 )
  {
    for( left_min = 0; left_min < len - i; left_min = right_max)
    {
      int j;
      right_min = left_max = left_min + i;
      right_max = left_max + i;
      j = left_min;
      if ( right_max > len )
        right_max = len;
      index = 0;
      while( left_min < left_max && right_min < right_max )
      {
        tmp[index++] = (list[left_min] > list[right_min] ? list[right_min++] : list[left_min++]);
      }
      while( left_min < left_max )
      {
        list[--right_min] = list[--left_max];
      }
      while( index > 0 )
      {
        list[--right_min] = tmp[--index];
      }
    }
  }
  free(tmp);
}
int main()
{
  int a[] = {288, 52, 123, 30, 212, 23, 10, 233};
  int n, mid;
  n = sizeof(a) / sizeof(a[0]);
  mid = n / 2;
  merge_sort(a, 0, n - 1);
  for(int k = 0; k < n; k++)
    printf("%d ", a[k]);
  printf("\n");
  return 0;
}

// Completed on 2014.10.11 18:20
// Language: C99
//
// 版权所有（C）codingwu  (mail: oskernel@126.com) 
// 博客地址：http://www.cnblogs.com/archimedes/
#include<stdio.h>
#include<stdlib.h>
void merge(int *array,const int first, const int mid, const int last)
{
  int i,index;
  int first1,last1;
  int first2,last2;
  int *tmp;
  tmp = (int *)malloc((last-first+1)*sizeof(int));
  if( tmp == NULL )
    return;
  first1 = first;
  last1 = mid;
  first2 = mid+1;
  last2 = last;
  index = 0;
  while( (first1 <= last1) && (first2 <= last2) )
  {
    if( array[first1] < array[first2] )
    {
      tmp[index++] = array[first1];
      first1++;
    }
    else{
      tmp[index++] = array[first2];
      first2++;
    }
  }
  while( first1 <= last1 )
  {
    tmp[index++] = array[first1++];
  }
  while( first2 <= last2 )
  {
    tmp[index++] = array[first2++];
  }
  for( i=0; i<(last-first+1); i++)
  {
    array[first+i] = tmp[i];
  }
  free(tmp);
}
void merge_sort(int *array, const int first, const int last)
{
  int mid = 0;
  if(first < last)
  {
    mid = (first + last) / 2;
    merge_sort(array, first, mid);
    merge_sort(array, mid + 1, last);
    merge(array, first, mid, last);
  }
}
int main()
{
  int a[] = {288, 52, 123, 30, 212, 23, 10, 233};
  int n, mid;
  n = sizeof(a) / sizeof(a[0]);
  mid = n / 2;
  merge_sort(a, 0, n - 1);
  for(int k = 0; k < n; k++)
    printf("%d ", a[k]);
  printf("\n");
  return 0;
}