常用的排序算法(八)——桶排序

桶排序算法对待排数列有一定的要求。数据长度必须一样,并且符合均匀分布。

桶排序的基本思想就是先创建一个含n个元素的数组,即就是创建n个桶。然后将待排的数进行哈希算法并链接到这个数组的各个元素中去,即就是将这些数分布到各个桶中去。为得到结果先对各个桶中的数据进行排序,然后按次序把各个桶的元素取出来即可。

代码如下:

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#include <stdio.h>
#include <time.h>
#include <stdlib.h>
const int N = 20;
const int M = 10;
struct chain
{
int key;
struct chain *next;
};
void init_bucket(struct chain a[], int n)
{
int i = 0;
for(; i < n; i++)
{
a[i].key = i * 10;
a[i].next = NULL;
}
}
int * generate(int a[], int n)
{
int i;
for(i = 0; i < n; i++)
{
a[i] = 0;
}
time_t t;
srand((unsigned)time(&t));
for(i = 0; i < n; i++)
{
a[i] = rand() % 100;
}
return a;
}
void print_array(int *a, int n)
{
int i = 0;
while(i < n)
{
printf("%4d", a[i]);
i++;
}
printf("\n");
}
void print_bucket(struct chain a[], int n)
{
int i = 0;
for(; i < n; i++)
{
printf("%4d", a[i].key);
}
printf("\n");
}
void insertChain(struct chain node, struct chain *newNode)
{
if(node.next == NULL)
{
node.next = newNode;
}
else
{
struct chain *p = node.next;
struct chain *q = p;
while(p->key < newNode->key)
{
q = p;
p = p->next;
}
newNode->next = q->next;
q->next = newNode;
}
}
void print_keys(struct chain a[], int n)
{
int i = 0;
for(; i < n; i++)
{
if(a[i].next != NULL)
{
struct chain *p = a[i].next;
while(p->next != NULL)
{
printf("%4d", p->key);
p = p->next;
}
printf("%4d", p->key);
}
}
}
void insert_bucket(struct chain a[], int *keys, int n)
{
int i = 0;
for(; i < n; i++)
{
struct chain *newNode = (struct chain *)malloc(sizeof(struct chain));
newNode->key = keys[i];
newNode->next = NULL;
struct chain *node = &a[keys[i] / 10];
if(node->next == NULL)
{
node->next = newNode;
}
else
{
struct chain *p = node->next;
struct chain *q = p;
while((p->key <= newNode->key) && (p->next != NULL))
{
q = p;
p = p->next;
}
newNode->next = q->next;
q->next = newNode;
}
}
}
int main()
{
struct chain heads[M];
init_bucket(heads, M);
printf("bucket: ");
print_bucket(heads, M);
int keys[N];
generate(keys,N);
printf("numbers:");
print_array(keys, N);
insert_bucket(heads, keys, N);
printf("ordered:");
print_keys(heads, M);
printf("\n");
return 0;
}