20分求助

#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
int n,m,a[1000001],zgf,zdf,b[1000001];
float pjs[1000001],g=-1;
int main()
{
	cin>>n>>m;
	for(int i=1;i<=n;i++)
	{
		zgf=-1;zdf=10000001;
		for(int j=1;j<=m;j++)
		{
			cin>>a[j];
			if(a[j]>zgf) zgf=a[j];
			if(a[j]<zdf) zdf=a[j];
		}
		sort(a+1,a+n+1);
		for(int j=2;j<=m-1;j++) b[j]=a[j];
		for(int j=1;j<=m;j++) pjs[i]=pjs[i]+b[j];
		pjs[i]=pjs[i]/(m-2);
		for(int j=1;j<=m;j++) a[j]=0,b[j]=0;
	}
	sort(pjs+1,pjs+n+1);
	g=pjs[n];
	printf("%2.lf",g);
	return 0;
}