莫名其妙的问题

[mcmay]

各位达人，下面这个简单程序是测试两个函数，一个函数直接从main中获取Sales结构体中sales数组的值，然后做一些规定的操作，如获取均值和极值，另一个是从使用者那里获取sales数组的值，然后做同样的操作，最后将两个结构体的各个信息打印出来。但是运行后，第二个数组的极值显示却有问题，最大值和最小值是一样的。

sales.h

//sales.h
#ifndef SALES_H_
#define SALES_H_

namespace SALES
{
	const int QUARTERS = 4;
	struct Sales
	{
		double sales[QUARTERS];
		double average;
		double max;
		double min;
	};
	// copies the lesser of 4 or n items from the array ar
	// to the sales member of s and computes and stores the
	// average, maximum, and minmum values of the entered items;
	// remaining elements of sales, if any, set to 0
	void setSales(Sales & s, const double ar[], int n);
	// gathers sales for 4 quarters integeractively, stores them
	// in the sales member of s and computes and stores the
	// average, maximum, and minmum values
	void setSales(Sales & s);
	// display all information in structure s
	void showSales(const Sales & s);
}
#endif

sale.cpp

// sales.cpp
#include <iostream>
#include "sales.h"

void SALES::setSales(Sales & s, const double ar[], int n)
{
	double sum = 0.;

	s.sales[0] = ar[0];
	s.max = s.sales[0];
	s.min = s.sales[0];
	sum += s.sales[0];

	for(int i = 1; i < n; i++)
	{
		s.sales[i] = ar[i];
		sum += s.sales[i];
		if(s.max < s.sales[i])
			s.max = s.sales[i];
		else if(s.min > s.sales[i])
			s.min = s.sales[i];
	}
	s.average = sum / n;
}

void SALES::setSales(Sales & s)
{
	using std::cout;
	using std::cin;
	using std::endl;

	for(int i = 0; i < SALES::QUARTERS; i++)
	{
		cout << "Enter number: ";
		cin >> s.sales[i];
	}
	double sum = 0.;
	s.max = s.sales[0];
	s.min = s.sales[0];

	sum += s.sales[0];

	for(int i = 1; i < SALES::QUARTERS; i++)
	{
		sum += s.sales[i];
		if(s.max < s.sales[i])
			s.max = s.sales[i];
		else if(s.min > s.sales[i]);
			s.min = s.sales[i];
	}
	s.average = sum / SALES::QUARTERS;
}

void SALES::showSales(const Sales & s)
{
	using std::cout;
	using std::endl;

	cout << "Sales:" << endl;
	for(int i = 0; i < SALES::QUARTERS; i++)
		cout << s.sales[i] << "\t";
	cout << "Average: " << s.average << endl;
	cout << "Max: " << s.max << endl;     // 这里显示Max和Min是一样的
	cout << "Min: " << s.min << endl;    
}

main.cpp

// main.cpp
#include <iostream>
#include "sales.h"

int main()
{
	SALES::Sales dat1, dat2;
	double ar[4] = {3.2, 4.8, 5.2, 6.3};

	SALES::setSales(dat1, ar, 4);
	SALES::setSales(dat2);
	std::cout << "Sales 1: " << std::endl;
	showSales(dat1);
	std::cout << "Sales 2: " << std::endl;
	showSales(dat2);

	return 0;
}

[幻夢之葉]

for(int i = 0; i < SALES::QUARTERS; i++) { cout << "Enter number: "; cin >> s.sales[i]; } 断点调试这操作之后sales的值