《C++ Primer Plus》(第6版)第5章编程练习
- 《C++ Primer Plus》(第6版)第5章编程练习
- 1. 计算闭区间内的整数和
- 2. 重新编写程序清单5.4
- 3. 累加
- 4. 投资价值
- 5. 销售情况
- 6. 销售情况2
- 7. 汽车
- 8. 销售情况2
- 9. 销售情况2
- 10. 销售情况2
《C++ Primer Plus》(第6版)第5章编程练习
1. 计算闭区间内的整数和
编写一个要求用户输入两个整数的程序。该程序将计算并输出这两个整数之间(包括这两个整数)所有整数的和。这里假设先输入较小的整数。例如,如果用户输入的是2和9,则程序将指出2~9之间所有整数的和为44。
代码:
#include <iostream>
using namespace std;
int main()
{int a, b, sum = 0;cout << "Please give me two numbers a and b(a<b),\n";cout << " and I will calculate the sum of the integers in the interval [a,b].\n";cout << "a: ";cin >> a;cout << "b: ";cin >> b;for (int i = a; i <= b; i++)sum += i;cout << "result:" << sum << endl;system("pause");return 0;
}
运行结果:
2. 重新编写程序清单5.4
使用 array对象(而不是数组)和 long double(而不是long long)重新编写程序清单5.4,并计算100!的值。
代码:
#include <iostream>
#include <array>
using namespace std;
const int ArrSize = 101;int main()
{array<long double, ArrSize> factorials;factorials[0] = factorials[1] = 1;for (int i = 2; i < ArrSize; i++)factorials[i] = i * factorials[i - 1];cout << "100!=" << factorials[100] << endl;system("pause");return 0;
}
运行结果:
3. 累加
编写一个要求用户输入数字的程序。每次输入后,程序都将报告到目前为止,所有输入的累计和。当用户输入0时,程序结束。
代码:
#include <iostream>
using namespace std;int main()
{int num, sum = 0;cout << "Please enter the number,\n";cout << "and I will calculate the cumulative sum of the input.\n";cout << "(enter 0 to end the program)" << endl;while (cin >> num && num != 0){sum += num;cout << "total:" << sum << endl;}cout << "Done!\n";system("pause");return 0;
}
运行结果:
4. 投资价值
Daphne 以10%的单利投资了100美元。也就是说,每一年的利润都是投资额的10%,即每年10美元:
利息=0.10×原始存款
而Cleo以5%的复利投资了100美元。也就是说,利息是当前存款(包括获得的利息的5%,:
利息=0.05×当前存款
Cleo在第一年投资100美元的盈利是5%——得到了105美元。下一年的盈利是105美元的5%—–即5.25美元,依此类推。请编写一个程序,计算多少年后,Cleo 的投资价值才能超过Daphne的投资价值,并显示此时两个人的投资价值。
代码:
#include <iostream>
using namespace std;
#define SIMPLE_RATE 0.10
#define COMPOUND_RATE 0.05
int main()
{double Daphne = 100, Cleo = 100;double principal = 100;unsigned year = 0;while (Cleo <= Daphne){Daphne += SIMPLE_RATE * principal;Cleo += COMPOUND_RATE * Cleo;year++;// cout << "year " << year << ":\n";// cout << "Daphne:" << Daphne << endl;// cout << "Cleo:" << Cleo << endl;}cout << year << " years later,";cout << " the investment value of Cleo exceeds the investment value of Daphne.\n";system("pause");return 0;
}
运行结果:
5. 销售情况
假设要销售《C++ For Fools》一书。请编写一个程序,输入全年中每个月的销售量(图书数量,而不是销售额)。程序通过循环,使用初始化为月份字符串的char*数组(或string对象数组逐月进行提示,并将输入的数据储存在一个int数组中。然后,程序计算数组中各元素的总数,并报告这一年的销售情况。
代码:
#include <iostream>
using namespace std;
#define MONTHS 12
const string months[12] = {"January","February","March","April","May","June","July","August","September","October","November","December"};int main()
{int sales[MONTHS];int sum = 0;for (int i = 0; i < MONTHS; i++){cout << "Please enter the sales volume for " << months[i] << ":";cin >> sales[i];}for (int i = 0; i < MONTHS; i++){cout << months[i] << " sales:" << sales[i] << endl;sum += sales[i];}cout << "Annual sales:" << sum << endl;system("pause");return 0;
}
运行结果:
6. 销售情况2
完成编程练习5,但这一次使用一个二维数组来存储输入——3年中每个月的销售量。程序将报告每年销售量以及三年的总销售量。
代码:
#include <iostream>
using namespace std;
#define YEAR 3
#define MONTH 12
const string months[12] = {"January","February","March","April","May","June","July","August","September","October","November","December"};int main()
{int sales[YEAR][MONTH] = {0};int annualSales[YEAR] = {0};int sum = 0;for (int i = 0; i < YEAR; i++){for (int j = 0; j < MONTH; j++){cout << "Please enter the sales volume for year " << i + 1 << " month " << months[j] << ":";cin >> sales[i][j];}}for (int i = 0; i < YEAR; i++){for (int j = 0; j < MONTH; j++){cout << "year " << i + 1 << " month " << months[i] << " sales:" << sales[i][j] << endl;annualSales[i] += sales[i][j];}}cout << "Annual sales:\n";for (int i = 0; i < YEAR; i++){cout << "year " << i + 1 << ":" << annualSales[i] << endl;sum += annualSales[i];}cout << "Total sales:" << sum << endl;system("pause");return 0;
}
7. 汽车
设计一个名为car的结构,用它存储下述有关汽车的信息:生产商(存储在字符数组或string对象中的字符串)、生产年份(整数)。编写一个程序,向用户询问有多少辆汽车。随后,程序使用new来创建一个由相应数量的car结构组成的动态数组。接下来,程序提示用户输入每辆车的生产商(可能由多个单词组成)和年份信息。请注意,这需要特别小心,因为它将交替读取数值和字符串(参见第4章)。最后,程序将显示每个结构的内容。该程序的运行情况如下:
How many cars do you wish to catalog? 2car #1:
Please enter the make: Hudson HornetPlease enter the year made: 1952
car #2:
please efter themake: Kaiserplease enter the year made:1951Here is your colrection :
1952 Hudson Hornet
1951 Kaiser
代码:
#include <iostream>
#include <string>
using namespace std;
struct Car
{string producer;int madeYear;
};
int main()
{int num = 0;cout << "How many cars do you wish to catalog? ";cin >> num;cin.get();Car *cars = new Car[num];for (int i = 0; i < num; i++){cout << "car #" << i + 1 << ":\n";cout << "Please enter the make: ";getline(cin, cars[i].producer);cout << "Please enter the year made: ";cin >> cars[i].madeYear;cin.get();}cout << "Here is your collection:\n";for (int i = 0; i < num; i++)cout << cars[i].madeYear << " " << cars[i].producer << endl;system("pause");return 0;
}
运行结果:
8. 销售情况2
代码:
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运行结果:
9. 销售情况2
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10. 销售情况2
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