C++ Primer Plus 第六版_编程练习（4）（Chapter_five 1-5）

编程工具用得好，搞起研究事半功倍。导师的意见是，学好C++，其他编程都不怕。暂时没有迫切的实战需要，于是决定从最基础的学起，挑了《C++ Primer Plus （第六版）》这本书，开始啃吧。编程练习还是一定要做的，每天一点，记在这里。

5_1

#include <iostream>
using namespace std;

int main()
{
int lower_bound_;
int upper_bound_;

cout << "Enter the lower bound: ";
cin >> lower_bound_;
cout << "Enter the upper bound: ";
cin >> upper_bound_;

int i;
int sum = 0;

for (i = lower_bound_; i <= upper_bound_; i++)
{
sum = sum + i;
}
cout << "Summer of the number between them is " << sum << endl;

return 0;
}

5_2

#include <iostream>
#include <array>
using namespace std;

const int Asize = 101;

int main()
{
array<long double, Asize> factorials;
factorials[0] = factorials[1] = 1;
for (int i = 2; i < Asize; i++)
{
factorials[i] = factorials[i - 1] * i;
}
for (int j = 0; j < Asize; j++)
{
cout << j << "! = " << factorials[j] << endl;
}

return 0;
}

5_3

#include <iostream>
using namespace std;

int main()
{
double i;
double sum = 0;

cout << "Enter a number(0 to qiut): ";
cin >> i;

while (i != 0)
{

sum = sum + i;
cout << "Summer of the number that you have entered is " << sum << endl;
cout << "Enter a number(0 to qiut): ";
cin >> i;
}

cout << "You have entered 0." << endl;
return 0;
}

5_4

#include <iostream>
using namespace std;

const double Value = 100;
const double Pre_1 = 0.10;
const double Pre_2 = 0.05;

int main()
{
double value_Daphne = Value;
double value_Cleo = Value;
int count_ = 1;

while (true)
{
value_Daphne += Value * Pre_1;
value_Cleo += value_Cleo * Pre_2;

if (value_Cleo > value_Daphne)
{
cout << "After " << count_ << " years, Cleo will get much more value than Daphne." << endl;
cout << "Cleo's value: " << value_Cleo << endl;
cout << "Daphne's value: " << value_Daphne << endl;
break;
}
count_++;
}

return 0;
}

5_5

#include <iostream>
#include <string>
using namespace std;

int main()
{
string month[12] = { "January", "February", "March", "April", "May", "June", "July",
"August", "September", "October", "November", "December" };
int num[12] = {};
int sum = 0;
cout << "Enter the sales of each month: " << endl;

for (int i = 0; i < 12; i++)
{
cout << month[i] << " : ";
cin >> num[i];
sum += num[i];
}

cout << "《C++ For Fools》 has been sold " << sum << " this year." << endl;

return 0;
}