C++PrimerPlus学习——第九章编程练习

前两天有事情去了，没有好好学，之后要补回来
9-1
main.cpp

#include <string.h>
#include <iostream>
#include"golf.h"const int GolfSize = 3;
int main()
{golf ann;setgolf(ann, "Ann Birdfree", 24);showgolf(ann);golf andy;setgolf(andy);golf g[GolfSize];int j = 0;for (int i = 0; i < GolfSize; i++){j = setgolf(g[i]);if (j == 1)showgolf(g[i]);else if (j == 0)break;}return 0;
}

golf.h

const int Len = 40;struct golf
{char fullname[Len];int handicap;
};
void setgolf(golf& g, const char* name, int hc);int setgolf(golf& g);void handicap(golf& g, int hc);void showgolf(const golf& g);

golf.cpp

#include <string.h>
#include <iostream>
#include"golf.h"void setgolf(golf& g, const char* name, int hc)
{strcpy_s(g.fullname, name);g.handicap = hc;
}int setgolf(golf& g)
{using std::cout;using std::cin;cout << "Please enter fullname: \n";cin.getline(g.fullname, 50);if (!strcmp(g.fullname, ""))return 0;cout << "Please enter handicap: \n";cin >> g.handicap;cin.get();return 1;
}
void handicap(golf& g, int hc)
{g.handicap = hc;
}void showgolf(const golf& g)
{using std::cout;cout << "fullname: " << g.fullname << "\n";cout << "handicap: " << g.handicap << "\n";
}

9-2
需要用getline才能获取空行

#include <iostream>
#include<string>
using namespace std;void strcount(const string str);int main()
{string input;char next;cout << "Enter a line:\n";getline(cin, input);while (input != ""){strcount(input);cout << "Enter the next line (empty line to quit):\n";getline(cin, input);}cout << "Bye\n";return 0;
}void strcount(const string str)
{static int total = 0;int count = 0;cout << "\"" << str << "\" contains ";count = str.size();total += count;cout << count << " characters\n";cout << total << " characters total\n";
}

9-3
同样需要stcpy_s
(1)

#include <iostream>
#include <string>struct chaff
{char dross[20];int slag;
};int main()
{using namespace std;chaff* cf = new chaff[2];strcpy_s(cf[0].dross, "gugugu");cf[0].slag = 6;strcpy_s(cf[1].dross, "biubiubiu");cf[1].slag = 9;for (int i = 0; i < 2; i++){cout << "dross, slag: " << cf[i].dross << ", " << cf[i].slag << endl;}//delete cf;<buffer>指定的是静态内存，不需要用delete释放return 0;
}

(2)

#include <iostream>
#include <string>struct chaff
{char dross[20];int slag;
};
const int BUF = 512;
const int N = 2;
char buffer[BUF];int main()
{using namespace std;chaff* cf = new (buffer) chaff[N];strcpy_s(cf[0].dross, "gugugu");cf[0].slag = 6;strcpy_s(cf[1].dross, "biubiubiu");cf[1].slag = 9;for (int i = 0; i < 2; i++){cout << "dross, slag: " << cf[i].dross << ", " << cf[i].slag << endl;}//delete cf;<buffer>指定的是静态内存，不需要用delete释放return 0;
}

9-4
main.cpp

#include <iostream>
#include"Sales.h"
using namespace SALES;int main()
{Sales a, b;double arr[3] = { 1.1, 22, 4.4 };setSales(a, arr, 3);showSales(a);setSales(b);showSales(b);return 0;
}

Sales.cpp

#include <iostream>
#include"Sales.h"
using namespace std;void SALES::setSales(Sales& s, const double ar[], int n)
{double sum = 0;double max = ar[0];double min = ar[0];if (n < QUARTERS){for (int i = 0; i < n; i++){s.sales[i] = ar[i];sum += ar[i];if (max < ar[i])max = ar[i];else if (min > ar[i])min = ar[i];}s.average = sum / n;s.max = max;s.min = min;for (int i = n; i < QUARTERS; i++)s.sales[i] = 0;}elsecout << "too long\n";
}
void SALES::setSales(Sales& s)
{double sum = 0;cout << "Enter four numbers:\n";for (int i = 0; i < QUARTERS; i++){std::cin >> s.sales[i];}double max = s.sales[0];double min = s.sales[0];for (int i = 0; i < QUARTERS; i++){sum += s.sales[i];if (max < s.sales[i])max = s.sales[i];else if (min > s.sales[i])min = s.sales[i];}s.average = sum / QUARTERS;s.max = max;s.min = min;
}
void SALES::showSales(const Sales& s)
{cout << "Sales" << "\n";cout << "Average: " << s.average << "\n";cout << "max: " << s.max << "\n";cout << "min: " << s.min << "\n";
}

Sales.h

#ifndef SALES_h_
#define SALES_h_
namespace SALES
{const int QUARTERS = 4;struct Sales{double sales[QUARTERS];double average;double max;double min;};void setSales(Sales& s, const double ar[], int n);void setSales(Sales& s);void showSales(const Sales& s);
}
#endif