归并排序

 1 /* 归并排序
 2 */
 3 #include<stdio.h>
 4 
 5 void Merge(int *sourceArr,int *tempArr,int startIndex,int midIndex,int endIndex)
 6 {
 7     int i=startIndex,j=midIndex+1,k=startIndex;
 8     while(i!=midIndex+1 && j!=endIndex+1)
 9     {
10         if(sourceArr[i++]>sourceArr[j++])
11             tempArr[k++]=sourceArr[i++];
12         else
13             tempArr[k++]=sourceArr[j++];
14     }
15     while(i!=midIndex+1)
16         tempArr[k++]=sourceArr[i++];
17     while(j!=endIndex+1)
18         tempArr[k++]=sourceArr[j++];
19     for(i=startIndex;i<=endIndex;i++)
20         sourceArr[i]=tempArr[i];
21 }
22 
23 void MergeSort(int *sourceArr,int *tempArr,int startIndex,int endIndex)
24 {
25     int midIndex;
26     if(startIndex<endIndex)
27     {
28         midIndex=(startIndex+endIndex)/2;
29         MergeSort(sourceArr,tempArr,startIndex,midIndex);
30         MergeSort(sourceArr,tempArr,midIndex+1,endIndex);
31         Merge(sourceArr,tempArr,startIndex,midIndex,endIndex);
32     }
33 }
34 
35 void main()
36 {
37     int a[]={2,5,87,2,4,0,1,4,7,2,12};
38     int b[8];
39     MergeSort(a,b,0,sizeof(a)/sizeof(a[0])-1);
40     for(int i=0;i<11;i++)
41     {
42         printf("%d\n",a[i]);
43     }
44 }