C++第五章课后

#include
using namespace std;
int main()
{
	cout << "Please input two number,now you can input first,which is smaller:";
	int first_num;
	int second_num;
	int sum = 0;
	cin >>first_num ;
	cout << "next:";
	cin >> second_num;
	for (int i = first_num; i <=second_num; i++) 
		sum = sum + i;
	cout << "整数和为：" << sum;
	return 0;
}

#include
#include
using namespace std;
const int ArSize = 100;
int main()
{
	array factorials;//需要声明头文件
	factorials[0] = factorials[1] = 1.0;
	for (int i = 2; i < ArSize + 1; i++)
	{
		factorials[i] = factorials[i - 1] * i;
	}
	for (int i = 0; i < ArSize + 1; i++)
	{
		cout << i << "! = " << factorials[i]< 
 
#include
using namespace std;
int main()
{
	double input_num=-1;
	double sum = 0;
	while (true )
	{
		cout << "请输入一个数字：(输入0时停止输入)" << endl;
		cin >> input_num;
		if (input_num == 0)
			break;
		sum = sum + input_num;
		cout << "现在输入之和为：" << sum << endl;
	}
	cout << "停止计数";
}
 

 
 
#include
using namespace std;
int main()
{
	double Daphne=100,Cleo =100;
	int year = 0;
	while (Daphne >= Cleo)
	{
		Daphne = Daphne + 10;
		Cleo = Cleo * 1.05;
		year++;
	}
	cout << "After " << year << "Yeas"< 
 
#include
using namespace std;
int main()
{   
	int years_num = 0;
	const char* month[12] = { "January", "February", "March", "April", "May", "June", "July", "August", "Septempber", "October", "November", "December" };//12个字符元素
	int month_num[12];
	for (int i = 0; i < 12; i++)
	{
		cout << month[i];
		cin >> month_num[i];
		years_num = years_num + month_num[i];
	}
	cout <<"year:" << years_num<
		cout << month[j] << ":" << month_num[j] << endl;
	}
}

 
 
#include
using namespace std;
int main()
{
	int years_num[3] = {0,0,0};
	const char* year[3] = { "first","second","third" };
	const char* month[12] = { "January", "February", "March", "April", "May", "June", "July", "August", "Septempber", "October", "November", "December" };//12个字符元素
	int month_num[3][12];
	for (int i = 0; i < 3; i++)
	{
		for (int j = 0; j < 12; j++)
		{
			cout << year[i] << " year " << month[j] << ":";
			cin >> month_num[i][j];
			years_num[i] = years_num[i] + month_num[i][j];
		}
	}
	for (int i = 0; i < 3; i++)
	{
		cout << year[i] << ":" << years_num[i] << endl;
	}
	
}
 
 
#include
#include
using namespace std;
struct car {
	string company;
	int year;
};
int main()
{
	int num = 0;
	cout << "How many cars do you wish to catalog?" << endl;
	cin >> num;
	cin.get();
	struct car* pcar = new struct car[num];
	for (int i = 0; i < num; i++)
	{
		cout << "Car #" << i+1 << ":" << endl;
		cout << "Please enter the make:";
		getline(cin, pcar[i].company);
		cout << "Please enter the year made:";
		cin >> pcar[i].year;
		cin.get();

	}
	cout << "Here is your collection:" << endl;
	for (int i = 0; i < num; i++)
	{
		cout << pcar[i].year << "  " << pcar[i].company << endl;
	}

}
 
 
#include
#include
using namespace std;
int main()
{
	int num = 0;
	char input_char[128];
	cout << "Enter words(to stop,type the word done):";
	while (cin >>input_char)
	{
		if (strcmp(input_char, "done"))//字符比较
			num++;
		else
			break;
	}
	cout << "you enter a total of " << num << " words";

}
 
 
#include
#include
using namespace std;
int main()
{
	int num = 0;
	string input_char;
	cout << "Enter words(to stop,type the word done):";
	while (cin >> input_char)
	{
		if (input_char!="done")//字符串可以直接比较，但是字符不可以
			num++;
		else
			break;
	}
	cout << "you enter a total of " << num << " words";

}
 
 
#include
using namespace std;
int main()
{
	int num = 0;
	cout << "Enter number of rows:";
	cin >> num;
	for (int i = 0; i < num ; i++)
	{
		for (int j = 0; j < num-i-1; j++)
		{
			cout << ".";
		}
		for (int k = 0; k < i+1; k++)
		{
			cout << "*" ;
		}
		cout << endl;
		
	}

}