参考http://www.cppblog.com/mysileng/archive/2013/04/06/199159.html

http://blog.csdn.net/syzcch/article/details/8050894

#include<stdio.h>  
#include<stdlib.h>  

#define MAX_LEVEL 10 //最大层数  

//节点  
typedef  struct nodeStructure
{
	int key;
	int value;
	struct nodeStructure *forward[1];
}nodeStructure;

//跳表  
typedef  struct skiplist
{
	int level;
	nodeStructure *header;
}skiplist;

//创建节点  
nodeStructure* createNode(int level, int key, int value)
{
	nodeStructure *ns = (nodeStructure *)malloc(sizeof(nodeStructure)+level*sizeof(nodeStructure*));
	ns->key = key;
	ns->value = value;
	return ns;
}

//初始化跳表  
skiplist* createSkiplist()
{
	skiplist *sl = (skiplist *)malloc(sizeof(skiplist));
	sl->level = 0;
	sl->header = createNode(MAX_LEVEL - 1, 0, 0);
	for (int i = 0; i<MAX_LEVEL; i++)
	{
		sl->header->forward[i] = NULL;
	}
	return sl;
}

//随机产生层数  
int randomLevel()
{
	int k = 1;
	while (rand() % 2)
		k++;
	k = (k<MAX_LEVEL) ? k : MAX_LEVEL;
	return k;
}

//插入节点  
bool insert(skiplist *sl, int key, int value)
{
	nodeStructure *update[MAX_LEVEL];
	nodeStructure *p, *q = NULL;
	p = sl->header;
	int k = sl->level;
	//从最高层往下查找需要插入的位置  
	//填充update  
	for (int i = k - 1; i >= 0; i--){
		while ((q = p->forward[i]) && (q->key<key))
		{
			p = q;
		}
		update[i] = p;
	}
	//不能插入相同的key  
	if (q&&q->key == key)
	{
		return false;
	}

	//产生一个随机层数K  
	//新建一个待插入节点q  
	//一层一层插入  
	k = randomLevel();
	//更新跳表的level  
	if (k>(sl->level))
	{
		for (int i = sl->level; i < k; i++){
			update[i] = sl->header;
		}
		sl->level = k;
	}

	q = createNode(k, key, value);
	//逐层更新节点的指针，和普通列表插入一样  
	for (int i = 0; i<k; i++)
	{
		q->forward[i] = update[i]->forward[i];
		update[i]->forward[i] = q;
	}
	return true;
}

//搜索指定key的value  
int search(skiplist *sl, int key)
{
	nodeStructure *p, *q = NULL;
	p = sl->header;
	//从最高层开始搜  
	int k = sl->level;
	for (int i = k - 1; i >= 0; i--){
		while ((q = p->forward[i]) && (q->key <= key))
		{
			if (q->key == key)
			{
				return q->value;
			}
			p = q;
		}
	}
	return NULL;
}

//删除指定的key  
bool deleteSL(skiplist *sl, int key)
{
	nodeStructure *update[MAX_LEVEL];
	nodeStructure *p, *q = NULL;
	p = sl->header;
	//从最高层开始搜  
	int k = sl->level;
	for (int i = k - 1; i >= 0; i--){
		while ((q = p->forward[i]) && (q->key<key))
		{
			p = q;
		}
		update[i] = p;
	}
	if (q&&q->key == key)
	{
		//逐层删除，和普通列表删除一样  
		for (int i = 0; i<sl->level; i++){
			if (update[i]->forward[i] == q){
				update[i]->forward[i] = q->forward[i];
			}
		}
		free(q);
		//如果删除的是最大层的节点，那么需要重新维护跳表的  
		for (int i = sl->level - 1; i >= 0; i--){
			if (sl->header->forward[i] == NULL){
				sl->level--;
			}
		}
		return true;
	}
	else
		return false;
}

void printSL(skiplist *sl)
{
	//从最高层开始打印  
	nodeStructure *p, *q = NULL;

	//从最高层开始搜  
	int k = sl->level;
	for (int i = k - 1; i >= 0; i--)
	{
		p = sl->header;
		while (q = p->forward[i])
		{
			printf("%d -> ", p->value);
			p = q;
		}
		printf("\n");
	}
	printf("\n");
}
int main()
{
	skiplist *sl = createSkiplist();
	for (int i = 1; i <= 19; i++)
	{
		insert(sl, i, i * 2);
	}
	printSL(sl);
	//搜索  
	int i = search(sl, 4);
	printf("i=%d\n", i);
	//删除  
	bool b = deleteSL(sl, 4);
	if (b)
		printf("删除成功\n");
	printSL(sl);
	system("pause");
	return 0;
}