C++ primer plus 第八章答案

#include <iostream>
#include <string>
using namespace std;
void Print(string *name, int time= 0);
int time = 0;
int main()
{
string name = "Hu Zeyu";
Print(&name,time);
Print(&name,time);
return 0;
}
void Print(string *name, int time)
{
for(int i = 0; i <= time; i++)
{
cout << *name << endl;
}
time++;
}

#include <iostream>
using namespace std;
struct Candy
{
char* brandname;
double weight;
int calories;
};
void Set(Candy &candybar, char* brandname = "Millenium Munch", double weight = 2.85, int calories = 350);
void Show(const Candy &candybar);
int main()
{
Candy test;
Set(test);
Show(test);
return 0;
}
void Set(Candy & candybar, char * brandname, double weight, int calories)
{
candybar.brandname = brandname;
candybar.weight = weight;
candybar.calories = calories;
}
void Show(const Candy & candybar)
{
cout << candybar.brandname << endl;
cout << candybar.weight << endl;
cout << candybar.calories << endl;
}

#include <iostream>
#include <string>
using namespace std;
void mytoupper(string & words);
int main()
{
string test;
cout << "Enter a string (q to quit): ";
while(getline(cin, test) && test != "q")
{
mytoupper(test);
cout << test << endl;
cout << "Next string(q to quit): ";
}
cout << "Bye.";
return 0;
}
void mytoupper(string & words)
{
int length = words.size();
for(int i = 0; i < length; i++)
{
words[i] = toupper(words[i]);
}
}

#include <iostream>
using namespace std;
#include <cstring> // for strlen(),strcpy()
struct stringy{
char * str;
int ct;
};
void set(stringy &beany, char []);
void show(const char [],int = 1);
void show(const stringy &, int = 1);
int main()
{
stringy beany;
char testing[] = "Reality isn't what it used to be.";
set(beany,testing);
show(beany);
show(beany,2);
testing[0] = 'D';
testing[1] = 'u';
show(testing);
show(testing, 3);
show("Done!");
return 0;
}
void set(stringy &beany,char testing[])
{
beany.ct = strlen(testing);
beany.str = new char[beany.ct + 1];
strcpy(beany.str, testing);
}
void  show(const char testing[],int length)
{
for(int i = 0; i < length; i++)
{
cout << testing << endl;
}
}
void show(const stringy &beany,int length)
{
for(int i = 0; i < length; i++)
{
cout << beany.str << endl;
}
}

#include <iostream>
using namespace std;
template <typename T>
T max5(T a[]);
int main()
{
int array1[] = {1,2,3,4,5};
double array2[] = {2.2,3.4,4.5,5.6,3.2};
cout << max5(array1) << endl;
cout << max5(array2) << endl;
return 0;
}
template <typename T>
T max5(T a[])
{
T max = a[0];
for(int i = 0; i < 5; i++)
{
max = max >= a[i] ? max : a[i];
}
return max;
}

#include <iostream>
#include <cstring>
using namespace std;

template <typename T>
T maxn(T num[], int length);

template <> char *maxn<char *>(char *num[], int length);
int main()
{
int a[6] = {1, 2, 3, 4, 5, 6};
double b[4] = {1.1, 2.2, 3.3, 4.4};
char *c[5] ={"apple","banana","egg","seal","elephant"};
std::cout << maxn(a, 6) << std::endl;
std::cout << maxn(b, 4) << std::endl;
std::cout << maxn(c, 5) << std::endl;
return 0;
}
template <typename T>
T maxn(T num[], int length)
{
T max = num[0];
for(int i = 0; i < length; i++)
{
max = max >= num[i] ? max : num[i];
}
return max;
}
template <> char *maxn<char *>(char *num[], int length)
{
int max = strlen(num[0]);
for(int i = 0; i < length; i++)
{
max = max >= (int)strlen(num[i]) ? max : strlen(num[i]);
}
for(int i = 0; i < length; i++)
{
if((int)strlen(num[i]) == max)
return num[i];
}
}

#include <iostream>
using namespace std;

template <typename T>
T SumArray(T arr[], int n);

template <typename T>
T SumArray(T * arr[], int n);

struct debts
{
char name[50];
double amount;
};
int main()
{
int things[6] = {13, 31, 103, 301, 310, 130};
struct debts mr_E[3] =
{
{"Ima Wolfe", 2400.0},
{"Ura Foxe", 1300.0},
{"Iby Stout", 1800.0}
};
double *pd[3];
for(int i = 0; i < 3; i++)
pd[i] = &mr_E[i].amount;
cout << SumArray(things, 6) << endl;
cout << "Listing Mr.E's debts:\n";
cout << SumArray(pd, 3) << endl;
return 0;
}
template <typename T>
T SumArray(T arr[], int n)
{
int sum = 0;
cout << "template A\n";
for(int i = 0; i < n; i++)
sum += arr[i];
return sum;
}
template <typename T>
T SumArray(T * arr[], int n)
{
cout << "template B\n";
int sum = 0;
for(int i = 0;i < n; i++)
sum += *arr[i];
return sum;
}