第九周作业（1）

 实验作业
1.调试分析课本每一个例题，有可能的话更改成2-3个方法的新程序；

2.编程实现课本每一个编程习题。

3. 有n个人围成一个圆圈，从第一个人开始报数，从1到3循环，凡是报3的退出圈子，问最后退出圈子的人是原来的几号。

4.一个班有5个学生，每一个学生有几门成绩（到底是几门自已定，或3或4或5或6），定义函数来完成下面功能：

    计算第2门课成的平均分；

    找出有2门以上成绩不及格的学生，并输出其学号和全部课程成绩；

    找出平均成绩在90以上或者全部课程在85分以上的学生。

 

课本例题

/******6.1*****/
#include<iostream>
using namespace std;
int main()
{
int a=10;
int *p;
p=&a;
cout<<"a = "<<a<<endl;
cout<<"p = "<<p<<endl;
cout<<"&a = "<<&a<<endl;
cout<<"*p= "<<*p<<endl;
cout<<"&p = "<<&p<<endl;
cout<<endl;
*p=15;
cout<<"a ="<<a<<endl;
cout<<"p = "<<p<<endl;
cout<<"&a = "<<&a<<endl;
cout<<"*p = "<<*p<<endl;
cout<<"&p = "<<&p<<endl;
return 0;
}

 

/******6.2*****/
#include<iostream>
using namespace std;
int main()
{
int a,b;
int *p=&a,*q=&b,*tp;
cout<<"请输入两个数:";
cin>>a>>b;
if(a<b)
{
tp=p;p=q;q=tp;
}
cout<<"初始的两个数为:"<<a<<" "<<b<<endl;
cout<<"从大到小排序后的数为:"<<*p<<" "<<*q<<endl;
return 0;
}

 

/******6.3*****/
#include<iostream>
using namespace std;
int main()
{
int a,b,temp;
int *p=&a,*q=&b;
cout<<"please input a and b:";
cin>>a>>b;
cout<<"初始的两个数为:"<<a<<" "<<b<<endl;
if(a<b)
{
temp=*p;*p=*q;*q=temp;
}
cout<<"从大到小排序后的数为:"<<*p<<" "<<*q<<endl;
return 0;
}

 

/******6.4*****/
#include<iostream>
using namespace std;
int main()
{
int a=10,b=10,*ptr1,*ptr2;
ptr1=&a;
ptr2=&b;
cout<<boolalpha<<(*ptr1==*ptr2)<<endl;
cout<<boolalpha<<(ptr1==ptr2)<<endl;
return 0;
}

 

/****6.5*****/
#include<iostream>
#include<iomanip>
using namespace std;
int main()
{
int a[10];
for(int i=0;i<10;i++)
a[i]=2*(i+1);
for(i=0;i<10;i++);
cout<<endl;
return 0;
}

/****6.6*****/
#include<iostream>
using namespace std;
int main()
{
char a[]="Hello world",b[20],*p,*q;
p=a,q=b;
for(;*p!='\0';p++,q++)
*q=*p;
*q='\0';
cout<<"string1 is:"<<a<<endl;
cout<<"string2 is:"<<b<<endl;
return 0;
}

/****6.7*****/
#include<iostream>
using namespace std;
int main()
{
char *p="student";
for(;*p!='\0';p++)
cout<<p<<endl;
return 0;
}

/****6.8*****/
#include<iostream>
using namespace std;
int main()
{
char *p="student";
for(int i=0;p[i]!='\0';i++)
cout<<p[i];
cout<<endl;
return 0;
}

/****6.9*****/
#include<iostream>
using namespace std;
int main()
{
char s[50];
char *p;
cout<<"please input a string:";
cin.get(s,50);
p=s;
for(;*p!='\0';)
p++;
cout<<"the length is:"<<p-s<<endl;
return 0;
}

/*******6.10****/
#include<iostream>
using namespace std;
int main()
{
int i=5,*p,**pp;
p=&i;
pp=&p;
cout<<&i<<'\t'<<i<<endl;
cout<<&p<<'\t'<<p<<'\t'<<*p<<endl;
cout<<&pp<<'\t'<<pp<<'\t'<<*pp<<'\t'<<**pp<<endl;
return 0;
}

/*******6.11****/
#include<iostream>
using namespace std;
int main()
{
int a[5]={1,2,3,4,5};
int *p[5]={&a[0],&a[1],&a[2],&a[3],&a[4]};
for(int i=0;i<=4;i++)
cout<<*p[i]<<'\t';
cout<<endl;
return 0;
}

/*******6.12****/
#include<iostream>
using namespace std;
int main()
{
char a[]="computer system",b[]="hardware",c[]="software";
char *p[4];
p[0]=a;
p[1]=b;
p[2]=c;
p[3]=NULL;
for(int i=0;p[i]!=NULL;i++)
cout<<p[i]<<endl;
return 0;
}

/*****6.13*****/
#include<iostream>
using namespace std;
int main()
{
char *weekname[]={"Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"};
int i;
while(1)
{
cout<<"please input week No.:";
cin>>i;
if(i<0||i>6)
break;
cout<<"week No."<<i<<"-->"<<weekname[i]<<endl;
}
return 0;
}

/*****6.14*****/
#include<iostream>
using namespace std;
int main()
{
char *p[]={"Rebacca","Heaven","Michael Chang","Linda Tsai"};
char *temp;
int i,j,n=4;
for(i=0;i<n-1;i++)
for(j=0;j<n-i;j++)
if(strcmp(p[j],p[j+1])>0)
{
temp=p[j];p[j]=p[j+1];p[j+1]=temp;
}
for(i=0;i<n;i++)
cout<<p[i]<<endl;
return 0;
}

/*****6.15*****/
#include<iostream>
using namespace std;
int main()
{
int a[2][3],*p[2];
int i,j;
p[0]=a[0];
p[1]=a[1];
for(i=0;i<2;i++)
for(j=0;j<3;j++)
a[i][j]=j+i;
for(i=0;i<2;i++)
for(j=0;j<3;j++)
{
cout<<"a["<<i<<"]["<<j<<"]:"<<a[i][j]<<endl;
}
return 0;

/*****6.16*****/
#include<iostream>
using namespace std;
int main()
{
int a[2][3],*p[2],**pp;
int i,j;
p[0]=&a[0][0];
p[1]=&a[1][0];
pp=p;
for(i=0;i<2;i++)
for(j=0;j<3;j++)
pp[i][j]=j+i;
for(i=0;i<2;i++)
for(j=0;j<3;j++)
{
cout<<"a["<<i<<"]["<<j<<"]:"<<*(*(pp+i)+j)<<endl;
}
return 0;
}

/*****6.17*****/
#include<iostream>
using namespace std;
int main()
{
char *a[]={"Rebacca","Heaven","Michael Chang",NULL};
char **pp;
pp=a;
while(*pp!=NULL)
cout<<*pp++<<endl;
return 0;
}

/*****6.18*****/
#include<iostream>
#include<iomanip>
using namespace std;
int main()
{
int a[2][3]={1,2,3,4,5,6};
int (*p)[3];
int i,j;
p=a;
for(i=0;i<2;i++)
{
for(j=0;j<3;j++)
cout<<setw(3)<<(*p)[j];
p++;
}
cout<<endl;
return 0;
}

/*****6.19*****/
#include<iostream>
using namespace std;
void display(int *,int *);
int main()
{
int a=5,b=10;
int *pa=&a;
int *pb=&b;
display(pa,pb);
return 0;
}
void display(int *p1,int *p2)
{
cout<<"paremeter 1 is"<<* p1<<endl;
cout<<"parameter 2 is"<<* p2<<endl;
}

/*****6.20*****/
#include<iostream>
using namespace std;
void lower(char *c);
int main()
{
char ch;
cout<<"input a uppercase character:";
cin>>ch;
lower(&ch);
cout<<"converted character:";
cout<<ch<<endl;
return 0;
}
void lower(char *pch)
{
if(*pch>='A'&&*pch<='z')
*pch+='a'-'A';
}

/*****6.21*****/
#include<iostream>
using namespace std;
void swap(int *,int *);
int main()
{
int a=3,b=4;
cout<<"交换前的数据为:";
cout<<"a ="<<a<<"\tb ="<<b<<endl;
swap(&a,&b);
cout<<"交换后的数据为:";
cout<<"a ="<<a<<"\tb="<<b<<endl;
return 0;
}
void swap(int *u,int *v)
{
int temp=*u;
*u=*v;
*v=temp;
}

/*****6.22*****/
#include<iostream>
using namespace std;
void input(int *s,int n);
int min(int *s,int n);
int main()
{
int a[10],small;
input(a,10);
small=min(a,10);
cout<<"the minimum is:"<<small<<endl;
return 0;
}
void input(int *s,int n)
{
cout<<"plea
9d03
se input "<<n<<"intergers:"<<endl;
for(int i=0;i<n;i++)
cin>>s[i];
}
int min(int *s,int n)
{
int min,i;
min=*s;
for(i=1;i<n;i++)
if(s[i]<min)
min=s[i];
return min;
}

/*****6.23*****/
#include<iostream>
using namespace std;
int main()
{
int func(int a,int b);
int (*pf)(int a,int b);
pf=func;
cout<<"please intput two integers:"<<endl;
int m,n;
cin>>m>>n;
int result=(*pf)(m,n);
cout<<"the result is "<<result<<endl;
return 0;
}
int func(int a,int b)
{
return a+b;
}

/*****6.24*****/
#include<iostream>
using namespace std;
int max(int,int);
int min(int,int);
int add(int,int);
void process(int,int,int(*fun)(int,int));
int main()
{
int a,b;
cout<<"enter a and b:"<<endl;
cin>>a>>b;
cout<<"max =";
process(a,b,max);
cout<<"min =";
process(a,b,min);
cout<<"sum=";
process(a,b,add);
return 0;
}
int max(int x,int y)
{
int z;
if(x>y)
z=x;
else
z=y;
return z;
}
int min(int x,int y)
{
int z;
if(x<y)
z=x;
else
z=y;
return z;
}
int add(int x,int y)
{
int z;
z=x+y;
return z;
}
void process(int x,int y,int(*fun)(int,int))
{
int result;
result=(*fun)(x,y);
cout<<result<<endl;
}