计数排序

#include<iostream>
using namespace std;
void print_array(int a[] , int n)
{
	for(int i = 0 ; i < n  ; i++)
	{
		cout<<" "<< a[i];
	}
	cout<<endl;
}
void count_sort(int *a,int length_ab,int *b,int k)
{
	
	int *c = new int[k];
	for(size_t i =0;i<=k;i++)
		c[i]=0;//数组初始化
	for(size_t j =0;j<length_ab;j++)
		c[a[j]]++;//重复数计数
	for(size_t m = 1;m<=k;m++)
		c[m]=c[m]+c[m-1];//小于或等于k的值
	//print_array(c,k+1);
	for(int d=length_ab-1;d>=0;d--)
	{
		
		b[c[a[d]]-1] = a[d];//定位
		c[a[d]]--;//重复数左移
	}

}

int main()
{
    int k = 5;
	int a[8] = {2,5,3,0,2,3,0,3};
	cout<<"before heapsort"<<endl;
	print_array(a,8);
	int b[8]={0,0,0,0,0,0,0,0};
	cout<<endl;
	count_sort(a,8,b,k);
	cout<<"after heapsort"<<endl;
	print_array(b,8);

}

解释见注释