自以为没什么问题，但样例都没过

#include<iomanip>
#include <iostream>
using  namespace std;
int main()
{
	int a, b, c = 0,n=0,k=0;//c是最大的数,n是最小数
	double ping = 0;
	cin >> a;
	cin >> b;
	n = b;
	k = k + b;
	for (int i = 2; i <= a; i++)
	{
		
		cin >> b;
		k = k + b;
	
		if (b > c)
		{
			c = b;
		}
		if (n > b) 
		{
			n = b;
		}

	}
	ping = (k - c - n)/(a-2) ;
	cout << fixed << setprecision(2) << ping;
	return 0;
}