学步园

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;
}

例题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;
}

例题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;
}

例题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;
}

例题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<<setw(4)<<a[i];
	cout<<endl;

	return 0;
}

例题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='\0';
	cout<<"string1 is:";
	cout<<a<<endl;
	cout<<"string2 is:";
	cout<<b<<endl;

	return 0;
}

例题6-7

#include<iostream>
using namespace std;

int main()
{
	char *p="student";
	for(; *p!='\0';p++)
		cout<<p<<endl;

	return 0;
}

例题6-8

#include<iostream>
using namespace std;

int main()
{
	char *p="student";
	for(int i=0;p[i]!='\0';i++)
		cout<<endl;

	return 0;
}

例题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;
}

例题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;
}

例题6-11

#include<iostream>
using namespace std;

int main()
{
	int a[5]={1,2,3,4,5};
	int *p[5]={&a[0],&a[0],&a[2],&a[3],&a[4]};
	for(int i=0;i<5;i++)
		cout<<*p[i]<<'\t';
	cout<<endl;

	return 0;
}

例题6-12

#include<iostream>
using namespace std;

int main()
{
	char a[]="computer system",b[]="hardware",c[]="sofrware";
	char *p[4];
	p[0]=a;
	p[1]=b;
	p[2]=c;
	p[3]=NULL;
	for(int i=0;p[1]!=NULL;i++)
		cout<<p[i]<<endl;

	return 0;
}

例题6-13

#include<iostream>
using namespace std;

int main()
{
	char * weekname[] = {"Sunday","Monday","Tuesday","Wednesday","Thursday","Firday","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;
}

例题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-1-i;j++)
			if(strcmp(p[j],p[j+1])>0)
			{
				temp = p[j]=p[j+1];p[j+1]=temp;
			}
			for(i=0;i<n;i++)
				cout<<p[i]<<endl;

			return 0;
}

例题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<<"]:";
				cout<<*(p[i]+j)<<endl;
			}

			return 0;
}

例题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<<"]:";
				cout<<*(*(pp+i)+j)<<endl;
			}

			return 0;
}