選擇排序

#include<stdio.h>
int max(int a[],int len)
{
	int maxid=0;
	int i=1;
	for(;i<len;i++ )
	{
		if(a[i]>a[maxid])
		{
			maxid=i;
		}
	}
	return maxid; //return the subscript what represents the max number of a[]
}
int main()
{
   	int a[]={0,1,2,5,6,4,2,36,58,4,1,57,21};
   	int len=sizeof(a)/sizeof(a[0]);
   	int i=len-1;
   	for(;i>0;i--)
	{
	   	int	maxid=max(a,i+1);
	   	//swap a[maxid],a[len-1]
	   	int t=a[maxid];
	   	a[maxid]=a[i];
	    a[i]=t; // Swap the max number with the last subscript 
	} 
	int j=0;
	for(;j<len;j++)
	{
		printf("%d ",a[j]);
	 } 
//	printf("%d\n",maxid);
    return 0;
}