第五章 编程练习

编程练习1

#include <iostream>using namespace std;int main(){    int a,b;    cout << "Please enter the start number: ";    cin >> a;    cout << "Please enter the end number: ";    cin >> b;    int sum = 0;    for (int i = a; i<=b; i++)        sum = sum + i;    cout << " the sum of all integers between " << a        << " and " << b << " is " << sum << endl;    system("pause");    return 0;}

编程练习2

#include <iostream>#include <array>using namespace std;const int ArSize = 101;int main(){    array<long double, ArSize> factorials;    factorials[1]  = factorials[0] = 1;    for(int i = 2; i < ArSize; i++)    {        factorials[i] = i * factorials[i-1];    }    for(int i = 0; i < ArSize; i++)    {        cout << i << "! = " << factorials[i] << endl;    }    system("pause");    return 0;}

编程练习3

#include <iostream>using namespace std;int main(){    int i;    int sum = 0;    cout << "Please enter a number: ";    cin >> i;    while(i != 0)    {        sum = sum + i;        cout << "Please enter another number: ";        cin >> i;    }    cout << "The sum of input numbers is : " << sum << endl;    system("pause");    return 0;}

编程练习4

#include <iostream>using namespace std;int main(){    float Daphne_Capital = 100;    float Cleo_Capital = 100;    float interest_fixed = 0.1;    float interest_flex = 0.05;    int year = 1;    do {        Daphne_Capital = Daphne_Capital + 100 * interest_fixed;        Cleo_Capital = Cleo_Capital * (1 + interest_flex);        year++;    }     while (Daphne_Capital > Cleo_Capital);    cout << "after " << year << " years, Cleo has more money than Daphne" << endl;    cout << "Daphne has " << Daphne_Capital << " dollars" << endl;    cout << "Cleo has " << Cleo_Capital << " dollars" << endl;    system("pause");    return 0;}

编程练习5

#include <iostream>using namespace std;int main(){    char * month[12] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun",        "Jul","Aug", "Sep", "Oct", "Nov", "Dec"};    int sales_month;    int sales_year = 0;    for (int i = 0; i < 12;i++)    {        cout << "Enter the number of books sold in " << month[i] << " : " ;        cin >> sales_month;        sales_year = sales_year + sales_month;    }    cout << "This year we have sold " << sales_year << " books" << endl;    system("pause");    return 0;}

编程练习6

#include <iostream>using namespace std;int main(){    int sales[3][12];    int total_sales = 0;    for (int year = 0; year < 3; year++)    {        int sales_year = 0;        for (int month = 0; month < 12; month++)        {             cout << " Enter the sales of year " << year+1                 << " month " << month +1 << " :";            cin >> sales[year][month];            sales_year = sales_year + sales[year][month];        }        cout << "This year we have sold " << sales_year << " books" << endl;        total_sales = total_sales + sales_year;    }    cout << "In total we have sold " << total_sales << " books" << endl;    system("pause");    return 0;}

编程练习7
这个练习使用了一个很笨的方法，因为结构数组是用动态指针声明的，所以赋值后还要把指针调回原位。学到后面函数之后会有更好的方法

#include <iostream>#include <string>using namespace std;struct car {    string brand;    int manufacture_year;};int main(){    int car_num;    cout << "How many cars do you wish to catalog? ";    cin>>car_num;    car *car_arr = new car[car_num];    for (int i = 0; i<car_num;i++,car_arr++)    {        cin.get();        cout << "Car #" << i+1 <<":" << endl;        cout << "Please enter the make: ";        string name;        getline(cin,name);        //cin.get();        cout << "Please enter the year made: ";        int y;        cin>>y;        //cin.get();        car_arr->brand = name;        car_arr->manufacture_year = y;    }    for (int i =0; i<car_num;i++)    {        car_arr--;    }    cout << "Here is your collection:" << endl;    for (int i=0; i<car_num;i++)    {        cout << car_arr[i].manufacture_year << "\t" << car_arr[i].brand << endl;    }    system("pause");    return 0;}

编程练习8

#include <iostream>using namespace std;const int ChSize = 100;int main(){    char word[ChSize];    int count = 0;    cout << "Please enter words: (type \"done\" to stop)" << endl;    do {        cin>>word;        if(!strcmp(word,"done"))            break;        else            count++;    } while(true);    cout << "In total you have input " << count << " words!" << endl;    system("pause");    return 0;}

编程练习9

#include <iostream>#include <string>using namespace std;int main(){    string word;    int count = 0;    cout << "Please enter a word: ";    getline(cin, word);    while(word !="done")    {        count ++;        cout << " Please enter another word: ";        getline(cin, word);    }    cout << "In total you have input " << count << " words!" << endl;    system("pause");    return 0;}

编程练习10

#include <iostream>using namespace std;int main(){    int row;    cout << "Please input how many rows to display: ";    cin >> row;    for (int i=0; i<row; i++)    {        int star = i+1;        int dot = row-i-1;        for (int j=0; j<dot;j++)            cout << " . ";        for (int k=0;k<star;k++)            cout << " * ";        cout << endl;    }    system("pause");    return 0;}