C++博客-风的方向-随笔分类-C++学习

判断回文数字

jince — Fri, 29 Oct 2010 11:57:00 GMT

今天培训的老师让我们做的题目。。。
我写了几个（不多说了比较累直接上代码了）：

#include<stdio.h>
#include<string.h>
#include<math.h>
#include<stdlib.h>
void Numtostring(int num,char s[])  //自定义数字转换成字符串函数
{
    int temp,i=0;
//    char *s;
//    s=(char *)malloc(500);
    //char s[500];
    while(num!=0)
    {
        temp=num%10;
        s[i]=temp+48;
        i++;
        num=num/10;
    }
    s[i]='\0';
    strrev(s);
}
int NumberTest0(int num)  //数字逆序，返回逆序值
{
    int temp;
    int n,i;
    int num0=0;
    n=log10(num);
    printf("n=%d\n",n);
    for(i=n;i>=0;i--)
    {
        temp=num%10;
        num=num/10;
        num0+=temp*pow(10,i);
        printf("num0=%d\n",num0);
    }
    return num0;
}
int StringTest(int num)//回文判断，字符串逆转思路
{
    char s[500],s1[500];
    Numtostring(num,s);//数字转换成字符串函数
    puts(s);
    strcpy(s1,s);
    strrev(s1);
    if(strcmp(s1,s)==0)
        printf("Yes\n");
    else
        printf("No\n");
    return 0;
}

int NumberTest1(int n)//回文判断老师解题思路听说是大神级的人物写的。。。
{
    int temp=0;
    int m=n;
    while(n)
    {
        temp=temp*10;
        temp+=n%10;
        n=n/10;
    }
    printf("%d\n",temp);
    if(temp==m)
        printf("Yes\n");
    else
        printf("No\n");
    return 0;
}
int main()
{

    int num,num0;
//    long n;
    char s[500];
    while(scanf("%d",&num)!=EOF)
    {
      /*num0=Test(num);
        printf("%d\n",num0);
        if(num0==num)
            printf("Yes\n");
        else
            printf("No\n");*/
    //    Numtostring(num,s);
    //    puts(s);
    //    StringTest(num);
        NumberTest1(num);
    }
    return 0;
}

jince 2010-10-29 19:57 发表评论

容器

jince — Fri, 03 Sep 2010 05:52:00 GMT

C++ 中vector容器，挺好用的，记录一下！按照vector容器函数说明测了一下，一一应验！
代码如下：

#include
#include
#include
#include
#include
using namespace std;
bool cmp(const int &a,const int &b)
{
    return a>b;
}
int main()
{
    vector v1;
    v1.push_back( 0 );
    v1.push_back( 1 );
    v1.push_back( 2 );
    v1.push_back( 3 );

    vector v2;
    v2.push_back( 5 );
    v2.push_back( 6 );
    v2.push_back( 7 );
    v2.push_back( 8 );

    cout << "Before, v2 is: ";
    for( vector::size_type i = 0; i < v2.size(); i++ ) {
      cout << v2[i] << " ";
    }
    cout << endl;

/**//* cout << "Before, v2 is: ";
    for( vector::iterator iter =v2.begin() ; iter < v2.end(); iter++ ) {
      cout << *iter << " ";
    }
    cout << endl;//迭代器，相当于指针的概念。。*/

  //  v2.insert( v2.end(), v1.begin(), v1.end() );//在v2末尾插入v1

  //  v2.insert(v2.end(),3,'3');    //在v2末尾插入3个51

  //  swap(v1,v2);
  //  v1.swap(v2);                    //交换

  //  printf("%d\n",v2.at(2));         // 输出指定位置值

  //  sort(v2.begin(),v2.end(),cmp); //排序，一直没弄明白cmp

  //  sort(v2.begin(),v2.end(),greater()); //递减排序

  //  sort(v2.begin(),v2.end(),less());  //递增排序

  //  v2.assign(v1.begin(),v1.end());//拷贝v1到v2

  //  v2.erase(v2.end()-1,v2.end()); //删除容器元素，不包括第一个数

  //  v2.clear();   //清空

  //  v2.resize(2);        //修改元素个数

    cout << "After, v2 is: ";
    for( vector::size_type j = 0; j < v2.size(); j++ ) {
      cout << v2[j] << " ";
    }
    return 0;
}

jince 2010-09-03 13:52 发表评论

C++ 重载流的提取操作

jince — Thu, 02 Sep 2010 14:08:00 GMT

      书上有一个用C++设计自己的输出/输入操作，涉及到运算符重载和流提取符重载，挺不错的！
      代码如下：
      COMPLEX.HPP文件

#include<iostream.h>
class COMPLEX {
public :
    COMPLEX(double r=0,double i=0);
    COMPLEX(const COMPLEX& other);
    COMPLEX operator +(const COMPLEX& other);
    COMPLEX operator -(const COMPLEX& other);
    COMPLEX operator -();
    COMPLEX operator =(const COMPLEX &other);
    friend ostream& operator <<(ostream& stream,COMPLEX& obj);
    friend istream& operator <<(istream& stream,COMPLEX& obj);
public :
    double real,image;
};

COMPLEX.CPP文件

//COMPLEX.CPP文件

#include "COMPLEX.HPP" //将头文件包括进去,不能写成include。。。

COMPLEX::COMPLEX(double r,double i)
{
    real=r;
    image=i;
    return ;
}

COMPLEX::COMPLEX(const COMPLEX& other)
{
    real=other.real;
    image=other.image;
    return ;
}

COMPLEX COMPLEX::operator +(const COMPLEX& other)   //运算符+重载  参数为COMPLEX类型，返回值为COMPLEX类型的引用，下同
{
    COMPLEX temp;

    temp.real=real+other.real;
    temp.image=image+other.image;
    return temp;
}

COMPLEX COMPLEX::operator -(const COMPLEX& other)
{
    COMPLEX temp;

    temp.real=real-other.real;
    temp.image=image-other.image;
    return temp;
}

COMPLEX COMPLEX::operator =(const COMPLEX& other)
{
    real=other.real;
    image=other.image;
    return *this;
}

ostream& operator<<(ostream& stream,COMPLEX& obj)   //流提取符重载有两个参数，第一个参数出现在<<操作符左侧，为ostream引用，第二个出现在操作符<<右侧，为COMPLEX引用，返回值是一个ostream的对象引用，下同
{
    stream<<obj.real;
    if(obj.image>0)  stream<<"+"<<obj.image<<"i";
    else if(obj.image<0) stream<<obj.image<<"i";
    return stream;
}

istream& operator>>(istream& stream,COMPLEX& obj)
{
    cout<<"Input real part:";
    stream>>obj.real;
    cout<<"input image part:";
    stream>>obj.image;
    return stream;
}

int main()
{
    COMPLEX c1,c2;

    cout<<"Input the first complex number c1:"<<endl;

    cin>>c1;

    cout<<"Input the second compex number c2:"<<endl;

    cin>>c2;

    cout<<"c1 is"<<c1<<endl;

    cout<<"c2 is"<<c2<<endl;

    cout<<"c1+c2 is "<<c2+c1<<endl;

    cout<<"c1-c2 is "<<c1-c2<<endl;
    //操作符原功能任存在

    int a=50,b=10;

    cout<<"A="<<a<<"\tB"<<b<<endl;

    cout<<"A+B is "<<a+b<<endl;

    cout<<"A-B is "<<a-b<<endl;

    a=-b;
    cout<<"A=-B,A="<<a<<"\tB"<<b<<endl;

    a=b;
    cout<<"A=B,A="<<a<<"\tB"<<b<<endl;
    return 0;
}

输出结果：

jince 2010-09-02 22:08 发表评论