c语言排序算法

最近又重新温习了一下排序算法，自己重新写了一下代码:

1.插入排序

void InsertSort(int a[],int N)

{

int i,j;

int tmp;

for(i = 1 ;i < N;i++)

{

tmp = a[i];

for(j = i-1;j >=0 ;j--)

{ 

if(a[j] < tmp)

{ 

break; 

}

a[j+1] = a[j];

}

a[j+1] = tmp;

}

}

2. shell排序(希尔排序）

   增量选择了5,3,1

void InsertSortByInc(int a[],int N, int inc)

{

int i,j;

int tmp;

for(i = inc; i < N; i++)

{

tmp = a[i];

for(j = i - inc; (j >=0 && a[j]>tmp); j-=inc)

{

a[j+inc] = a[j];

}

a[j+inc] = tmp;

}

}

void ShellSort(int a[],int N)

{

int inc;

for(inc = 5; inc >= 1 ;inc = inc - 2)

{

InsertSortByInc(a,N,inc);

}

}

3.归并排序（merge sort）

void Merge(int a[],int c[],int lt,int cr,int rt)

{

int i,j;

int k;

  i = lt;

  j = cr+1;

  k = lt;

while(i<=cr && j<=rt)

{

if(a[i] < a[j])

{

c[k] = a[i];

i++;

}

else

{

c[k] = a[j];

j++;

}

k++;

}

for(;i<=cr;i++)

c[k++] = a[i];

for(;j<=rt;j++)

c[k++] = a[j];

for(i = lt;i<=rt;i++)

a[i] = c[i];

}

void MergeSortExc(int a[],int c[],int left,int right)

{

int center;

if(left < right)

{

center = (left+right)/2;

MergeSortExc(a,c,left,center);

MergeSortExc(a,c,center+1,right);

Merge(a,c,left,center,right);

}

}

void MergeSort(int a[], int N)

{

int c[N];

MergeSortExc(a,c,0,N-1);

}

4.heap sort（堆排序）

void down(int a[],int i,int N)

{

int index;

int tmp;

tmp = a[i];

index = 2*i+1;

if(index > N-1)

return;

do

{ 

if((index+1 <= N-1) && (a[index+1] > a[index]))

index = index+1;

if(a[index] <= tmp)

break;

a[i] = a[index];

i = index;

index = 2*i+1;

}while(index<=N-1);

a[i] = tmp;

}

void BuildHeap(int a[],int N)

{

int i;

for(i = (N-1)/2;i>=0;i--)

{

down(a,i,N);

}

}

void HeapSort(int a[],int N)

{

int i;

int tmp;

BuildHeap(a,N);

for(i = (N-1);i>0;i--)

{

 tmp = a[0];

 a[0] = a[i];

 a[i] = tmp;

 down(a,0,i);

}

}