PTA乙级 （1012 数字分类 (20分)，四舍五入小数点后一位）

1012 数字分类 (20分)

https://pintia.cn/problem-sets/994805260223102976/problems/994805311146147840

四舍五入保留小数点后一位：

double Scale_4(double argu)
{
    return floor(argu*10.0 + 0.5) / 10.0;
}　　　

代码：

#include <iostream>
#include <cstdio>
#include <cstring>
#include <string>
#include <cmath>
#include <algorithm>
using namespace std;
int main()
{
	bool flag=false;
	int n,arr[1002];
	int sum1=0,sum2=0,sum3=0,sum4=0,sum5=0,max5=-1;
	double value=0;
	int i=0,j=0,k=0,count=0;
	cin>>n;
	for(i=0;i<n;i++) cin>>arr[i];
	for(i=0;i<n;i++)
	{
	   if((arr[i]%5==0)&&(arr[i]%2==0)) sum1+=arr[i];
	   else if(arr[i]%5==1)
	   {
	   	  k++;
	   	  if(k%2==0) sum2-=arr[i];
	   	  else sum2+=arr[i];
	   }
	   else if(arr[i]%5==2) sum3++;
	   else if(arr[i]%5==3) {sum4+=arr[i];count++;}
	   else if(arr[i]%5==4&&arr[i]>max5) max5=arr[i];  	
	}
	if(count!=0) value=sum4*1.0/count;
	if(sum1!=0) cout<<sum1;else cout<<"N";
	if(k>0) cout<<" "<<sum2;else cout<<" N"; 
	if(sum3!=0) cout<<" "<<sum3;else cout<<" N";
	if(sum4!=0) printf(" %.1f",floor(value*10.0 + 0.5) / 10.0);else cout<<" N";
	if(max5!=-1) cout<<" "<<max5;else cout<<" N";
	return 0; 
}