C++ primer plus 第八章编程练习

1、

/********************************************************************************************
Author:Tang Qingyun
Time:2017/03/09
From:C++ primer plus 第八章编程练习 第1题
*********************************************************************************************/

#include "stdafx.h"
#include<iostream>
#include<string>
using namespace std;
void print(const char *str, int n=0);

int main()
{
const char * str="well,well,well";
cout << "++++++++++++++++++++++++\n";
print(str);
cout << "++++++++++++++++++++++++\n";
print(str, 3);
return 0;
}
void print(const char *str, int n)
{
if (n <= 0)
n = 1;
for (int i = 0; i < n;i++)
cout << str<<endl;

}

2、

/********************************************************************************************
Author:Tang Qingyun
Time:2017/03/09
From:C++ primer plus 第八章编程练习 第2题
*********************************************************************************************/

#include "stdafx.h"
#include<iostream>

using namespace std;
struct CandyBar
{
char Name[20];
double Weight;
int Calories;
};
void fill(CandyBar &a,const char * N = "Millennium", const double W = 2.85,const int C = 350);
void show(const CandyBar &b);

int main()
{
CandyBar s,z;
fill(s);
show(s);
char name[30];
double weight;
int calories;
cout << "Please enter the name:";
cin.getline(name, 30);
cout << "Please enter the weight:";
cin >> weight;
cout << "Please enter the calories:";
cin >> calories;
fill(z, name, weight, calories);
show(z);
return 0;
}
void fill(CandyBar &a, const char* N, const double W,const int C)
{
strcpy_s(a.Name , N);
a.Weight = W;
a.Calories = C;
}
void show(const CandyBar &b)
{
cout << "Name:" << b.Name << endl;
cout << "Weight:" << b.Weight << endl;
cout << "Calories:" << b.Calories << endl;
}

3、

/********************************************************************************************
Author:Tang Qingyun
Time:2017/03/09
From:C++ primer plus 第八章编程练习 第3题
*********************************************************************************************/

#include "stdafx.h"
#include<iostream>
#include<string>
#include<cctype>

using namespace std;
void transform(string &str);

int main()
{
cout << "Enter a string (q to quit):";
string s;
getline(cin, s);
while (s != "q")
{
transform(s);
cout << s << endl;
cout << "Next string (q to quit):";
getline(cin, s);
}
cout << "Bye." << endl;
return 0;
}
void transform(string &str)
{
for (int i = 0; i < str.size(); i++)
str[i] = toupper(str[i]);
}

4、

/********************************************************************************************
Author:Tang Qingyun
Time:2017/03/09
From:C++ primer plus 第八章编程练习 第4题
*********************************************************************************************/

#include "stdafx.h"
#include<iostream>
#include<string>
using namespace std;

struct stringy
{
char *str;
int ct;
};

void set(stringy &s, const char *str);
void show(const stringy&s, int n=1);
void show(char *str, int n=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 &s, const char *str)
{
int len = strlen(str);
s.ct = len;
s.str = new char(len + 1);
strcpy_s(s.str,(len+1), str);
}

void show(const stringy&s,int n)
{
for (int i = 0; i < n; i++)
cout << s.str<<endl;

}
void show(char *str, int n)
{
for (int i = 0; i < n; i++)
cout << str << endl;
}

5、

/********************************************************************************************
Author:Tang Qingyun
Time:2017/03/09
From:C++ primer plus 第八章编程练习 第6题
*********************************************************************************************/

#include "stdafx.h"
#include<iostream>
//#include<string>
using namespace std;
template<typename T>
T max5(T z[]);

int main()
{
int a[5] = { 1, 3, 6, 2, 5 };
double b[5] = { 2.4, 5.1, 1.6, 3.3, 9.1 };
int amax;
double bmax;
amax = max5(a);
cout << "amax=" << amax << endl;
bmax = max5(b);
cout << "bmax=" << bmax << endl;

return 0;
}
template<typename T>
T max5(T z[])
{
T temp;
temp = z[0];
for (int i = 1; i < 5; i++)
{
if (temp <= z[i])
temp = z[i];
}
return temp;
}

6、

/********************************************************************************************
Author:Tang Qingyun
Time:2017/03/09
From:C++ primer plus 第八章编程练习 第6题
*****************
4000
****************************************************************************/

#include "stdafx.h"
#include<iostream>
//#include<string>
using namespace std;
template<typename T>
T maxn(T z[],int n);
template<>char* maxn(char * a[], int n);

int main()
{
int a[6] = { 1, 3, 6, 2, 5,2 };
double b[4] = { 5.1, 1.6, 3.3, 9.1 };
char *c[5] = { "sss", "s", "sssssssss", "ss", "ssss" };
cout << "amax=" << maxn(a, 6) << endl;
cout << "bmax=" << maxn(b, 4) << endl;
cout << "clongest=" << maxn(c, 5) << endl;

return 0;
}
template<typename T>
T maxn(T z[],int n)
{
T temp;
temp = z[0];
for (int i = 1; i < n; i++)
{
if (temp <= z[i])
temp = z[i];
}
return temp;
}
template<>char* maxn(char * a[], int n)
{
char * temp = a[0];
for (int i = 0; i < n; i++)
{
if (strlen(temp) < strlen(a[i]))
temp=a[i];
}
return temp;
}

7、

/********************************************************************************************
Author:Tang Qingyun
Time:2017/03/09
From:C++ primer plus 第八章编程练习 第7题
*********************************************************************************************/

#include "stdafx.h"
#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 amout;
};

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].amout;

cout << "Sum of Mr.E's counts of things:\n" << SumArray(things, 6) << endl;
cout << "Sum of Mr.E's debts:\n" << SumArray(pd, 3) << endl;
return 0;
}

template<typename T>
T SumArray(T arr[], int n)
{
cout << "template A\n";
T sum = 0;
for (int i = 0; i < n; i++)
{
sum += arr[i];
}
return sum;
}
template<typename T>
T SumArray(T * arr[], int n)
{
T sum = 0;
cout << "template B\n";
for (int i = 0; i < n; i++)
{
sum += *arr[i];
}
return sum;
}