归并排序

void Merge(int sourceArr[], int tempArr[], int startIndex, int midIndex, int endIndex)
{
int i = startIndex, j = midIndex + 1, k = startIndex;
while (i != midIndex + 1 && j != endIndex + 1)
{
if (sourceArr[i] > sourceArr[j])
tempArr[k++] = sourceArr[i++];
else
tempArr[k++] = sourceArr[j++];
}
while (i != midIndex + 1)
tempArr[k++] = sourceArr[i++];
while (j != endIndex + 1)
tempArr[k++] = sourceArr[j++];
for (i = startIndex; i <= endIndex; i++)
sourceArr[i] = tempArr[i];
}

//内部使用递归
void MergeSort(int sourceArr[], int tempArr[], int startIndex, int endIndex)
{
int midIndex;
if (startIndex < endIndex)
{
midIndex = (startIndex + endIndex) / 2;
MergeSort(sourceArr, tempArr, startIndex, midIndex);
MergeSort(sourceArr, tempArr, midIndex + 1, endIndex);
Merge(sourceArr, tempArr, startIndex, midIndex, endIndex);
}
}

int main(int argc, char * argv[])
{
int a[8] = { 50, 10, 20, 30, 70, 40, 80, 60 };
int i, b[8];
MergeSort(a, b, 0, 7);
for (i = 0; i<8; i++)
printf("%d ", a[i]);
printf("\n");
return 0;
}

归并排序

原文：http://www.cnblogs.com/qifengle/p/4921319.html