第五章编程练习

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

int main() {
    //编程练习5.1
    /*int num1, num2;
    cout << "input num1:";
    cin >> num1;
    cout << "input num2:";
    cin >> num2;
    int sum = 0;
    for (int i = num1; i <= num2; i++) {
        sum += i;
    }
    cout << "sum=" << sum << endl;*/

    //5.2
    /*array<long double, 101> factor;
    factor[0] = factor[1] = 1;
    for (int i = 2; i < 101; i++) {
        factor[i] = i*factor[i - 1];
    }
    for (int i = 0; i < 101; i++) {
        cout << i << "!=" << factor[i] << endl;
    }*/

    //5.3
    /*int num, sum = 0;
    cin >> num;
    while (num != 0) {
        sum += num;
        cout << "current sum is " << sum << endl;
        cin >> num;
    }*/

    //5.4
    /*int d = 100, c = 100, i = 0;
    do {
        d = d + 10;
        c = 1.05*c;
        i++;
    } while (c <= d);
    cout << "After " << i << " years." << endl;*/

    //5.5
    /*string month[12] = { "Janu","Febr","Mar","April","May","June",
        "July","Aug","Sept","Oct","Nov","Dec" };
    int sails[12];
    int sum = 0;
    for (int i = 0; i < 12; i++) {
        cout << "Input sail of month " << month[i] << endl;
        cin >> sails[i];
        sum += sails[i];
    }
    cout << "sum=" << sum << endl;*/

    //5.6
    /*int sails[3][12];
    int sum1 = 0, sum2 = 0, sum3 = 0, sum = 0;
    for (int i = 0; i < 3; i++)
        for (int j = 0; j < 12; j++)
            cin >> sails[i][j];

    for (int i = 0; i < 12; i++) {
        sum1 += sails[0][i];
        sum2 += sails[1][i];
        sum3 += sails[2][i];
    }
    sum += sum1 + sum2 + sum3;
    cout << "The first year's sails is " << sum1 << endl;
    cout << "The second year's sails is " << sum2 << endl;
    cout << "The third year's sails is " << sum3 << endl;
    cout << "The total sails is " << sum << endl;*/

    //5.7
    /*struct car {
        string producter;
        int year;
    };
    int num;
    cout << "The num of car:";
    cin >> num;
    car *c = new car[num];
    for (int i = 0; i < num; i++) {
        cout << "car #" << i << endl;
        cout << "please enter the maker:";
        cin.get();
        getline(cin, c[i].producter);
        cout << "please enter the year make:";
        cin >> c[i].year;
    }
    cout << "here is your collection:" << endl;
    for (int i = 0; i < num; i++) {
        cout << c[i].year << " " << c[i].producter << endl;
    }*/

    //5.8
    /*char *words = new char[20];
    int count = 0;
    cout << "enter word,done over:" << endl;
    do {
        cin.get(words, 20).get();
        count++;
    } while (words != "done");
    cout << "you entered " << count << " word." << endl;*/

    //5.9
    /*string str;
    int count = 0;
    do {
        count++;
        cin >> str;
    } while (str != "done");
    cout<< "you entered " << count << " word." << endl;*/

    //5.10
    int num;
    cout << "enter number of rows:";
    cin >> num;
    for (int i = 0; i < num; i++) {
        char cc[40];
        for (int j = 0; j < (num - i - 1); j++)
            cout << '.';
        for (int j = 0; j < (i + 1); j++)
            cout << '*';
        cout << endl;
    }
    return 0;
}