C++ Primer Plus | chapter 5 课后编程练习

第五章 循环和关系表达式

#include<iostream>
using namespace std;
int main()
{
    
    
    int a, b;
    int sum = 0;
    cout << "Please enter the first integer: ";
    cin >> a;
    cout << "Please enter the second integer: ";
    cin >> b;
    while(a > b)
    {
    
    
        cout << "WRONG INPUT!" << endl;
        cout << "Please enter the first integer: ";
        cin >> a;
        cout << "Please enter the second integer: ";
        cin >> b;
    }
    for(int i=a; i<=b; i++)
        sum += i;
    cout << "The sum is: " << sum << endl;
    return 0;
}

#include<iostream>
#include<array>
using namespace std;
const int ArSize = 16;
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;
    long double ans = factorials[ArSize-1];
    for(int i=ArSize; i<=100; i++)  ans *= i;
    cout << "100! = " << ans;
    return 0;
}

#include<iostream>
using namespace std;
int main()
{
    
    
    long long sum = 0;
    long long tmp;
    cin >> tmp;
    while(tmp != 0)
    {
    
    
        sum += tmp;
        cout << sum << endl;
        cin >> tmp;
    }
    return 0;
}

#include<iostream>
using namespace std;
int main()
{
    
    
    double daphne = 100, cleo = 100;
    int cnt_yr = 0;
    while(cleo <= daphne)
    {
    
    
        daphne += 10;
        cleo += cleo*0.05;
        cnt_yr++;
    }
    cout << cnt_yr << endl;
    return 0;
}

#include<iostream>
using namespace std;
int main()
{
    
    
    char* month[12] = {
    
    "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};
    int sales[12];
    int sum = 0;
    for(int i=0; i<12; i++)
    {
    
    
        cout << month[i] << ": ";
        cin >> sales[i];
        sum += sales[i];
    }
    cout << "sum: " << sum << endl;
    return 0;
}

#include<iostream>
using namespace std;
int main()
{
    
    
    char* month[12] = {
    
    "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};
    int sales[3][12];
    int sum[3] = {
    
    0};
    int total = 0;
    for(int i=0; i<3; i++)
    {
    
    
        cout << "Year " << i+1 << ": " << endl;
        for(int j=0; j<12; j++)
        {
    
    
            cout << month[j] << ": ";
            cin >> sales[i][j];
            sum[i] += sales[i][j];
        }
    }
    for(int i=0; i<3; i++)
    {
    
    
        cout << "Year " << i+1 << ": " << sum[i] << endl;
        total += sum[i];
    }
    cout << "Total: " << total << endl;
    return 0;
}

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

#include<iostream>
#include<cstring>
using namespace std;
int main()
{
    
    
    char ch[20];
    int cnt = 0;
    cin >> ch;
    while(strcmp(ch, "done") != 0)
    {
    
    
        cnt++;
        cin >> ch;
    }
    cout << "Total: " << cnt << " words";
    return 0;
}

#include<iostream>
#include<cstring>
#include<string>
using namespace std;
int main()
{
    
    
    string ch;
    int cnt = 0;
    cin >> ch;
    while(ch != "done")
    {
    
    
        cnt++;
        cin >> ch;
    }
    cout << "Total: " << cnt << " words";
    return 0;
}

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