定期存款利息計算

輸入存款金額並選擇存款種類，計算出利息（不計利息稅）和本息合計。根據選擇的存款種類，確定利率和存期後計算。
提示：利息=金額×年利率×存期（單位：年，3個月爲0.25年，6個月爲0.5年）。
例如：1000元存6個月，利息=1000×0.033×0.5=16.5元

利率使用2011年7月7日公佈的年利率：3個月  3.10%，6個月 3.30%，一年 3.50%，二年 4.40%，三年 5.00%，五年 5.50%。

參考博文：定期存款利息計算器

#include <iostream>

using namespace std;

void main()
{
	cout << "Welcome to use my Interest-Calculator" << endl;
	cout << "Interest rate standard is: " << endl;
	cout << "mode 1: " << "3 months 3.10%" << endl;
	cout << "mode 2: " << "6 months 3.30%" << endl;
	cout << "mode 3: " << "1 year 3.50%" << endl;
	cout << "mode 4: " << "2 year 4.40%" << endl;
	cout << "mode 5: " << "3 year 5.00%" << endl;
	cout << "mode 6: " << "5 year 5.50%" << endl;
	cout << "Please input your deposit mode: " << endl;
	int mode;
	cin >> mode;
	if(mode >=1 && mode <= 6)
	{
		cout << "Please input your deposit money: " << endl;
		double money;
		cin >> money;
	
		double interest_rate[] = {0.0310,0.0330,0.0350,0.0440,0.0500,0.0550};
		double dTime[] = {0.25,0.5,1,2,3,5};
		double interest = 0.0;
		interest = money * interest_rate[mode - 1] * dTime[mode - 1];
		cout << "The final interest is: " << interest << endl;
		system("pause");
	}

}

爲了使用容器這一概念，重新寫爲下面的程序：

#include <iostream>
#include <vector>

using namespace std;

void main()
{
	cout << "Welcome to use my Interest-Calculator" << endl;
	cout << "Interest rate standard is: " << endl;
	cout << "mode 1: " << "3 months 3.10%" << endl;
	cout << "mode 2: " << "6 months 3.30%" << endl;
	cout << "mode 3: " << "1 year 3.50%" << endl;
	cout << "mode 4: " << "2 year 4.40%" << endl;
	cout << "mode 5: " << "3 year 5.00%" << endl;
	cout << "mode 6: " << "5 year 5.50%" << endl;
	cout << "Please input your deposit mode: " << endl;
	int mode;
	cin >> mode;
	if(mode >=1 && mode <= 6)
	{
		cout << "Please input your deposit money: " << endl;
		double money;
		cin >> money;
		//vector<double>::size_type V1[] = {0.0310,0.0330,0.0350,0.0440,0.0500,0.0550};
		//vector<double>::size_type V2[] = {0.25,0.5,1,2,3,5};
		double V1[] = {0.0310,0.0330,0.0350,0.0440,0.0500,0.0550};
		double V2[] = {0.25,0.5,1,2,3,5};
		vector<double> interest_rate(V1,V1 + 6);
		vector<double> dTime(V2,V2 + 6);
		double interest;
		interest = interest_rate[mode - 1] * dTime[mode - 1] * money;
		cout << "The final interest is: " << interest << endl;
		system("pause");
	}
}

這裏其實完全不需要用容器去實現，只是爲了熟悉容器而故意這麼做。另外，被註釋的兩行，我把數組類型定義成 vector<double>::size_type，對最後的結果完全不起作用，輸出始終是0。只有老老實實定義成double,最後的結果才起作用，不知道這是怎麼回事？