学习map映照容器

# include<iostream>
# include<map>
# include<cstdio>
using namespace std;
struct myComp
{
    bool operator()(const int &a, const int &b)
    {
        if(a!=b)
        {
            return a>b;
        }
        else
        {
            return a>b;
        }
    }
};
struct Info
{
    string name;
    float score;
    bool operator < (const Info &a)const
    {
        return a.score < score;
    }
};
int main(int argc,const char * argv[])
{
    /*----------------------------------------*/
    //map创建，元素的插入和遍历
    //map<string,float>m;
    //m["Jack"] = 98.5;
    //m["Bomi"] = 96.0;
    //m["Kate"] = 97.5;
    //map<string,float>::iterator it;

    //for(it = m.begin();it!=m.end();it++)
    //{
    //    cout<<(*it).first<<":"<<(*it).second<<endl;
    //}

    /*---------------------------------------*/
    //删除元素
    //map<int,char>m;
    //m[25] = 'm';
    //m[28] = 'k';
    //m[10] = 'x';
    //m[30] = 'a';
    //m.erase(28);

    //map<int,char>::iterator it;
    //for(it = m.begin();it!=m.end();it++)
    //{
    //   cout<<(*it).first<<":"<<(*it).second<<endl;
    //}



    /*----------------------------------------*/
    //元素的反向逆序
    //map<int,char>m;
    //m[25] = 'm';
    //m[28] = 'k';
    //m[10] = 'x';
    //m[30] = 'a';

    //map<int,char>::reverse_iterator it;
    //for(it = m.rbegin();it!=m.rend();it++)
    //{
    //    cout<<(*it).first<<":"<<(*it).second<<endl;
    //}


    /*----------------------------------------*/
    //元素的搜索
    //map<int,char>m;
    //m[25] = 'm';
    //m[28] = 'k';
    //m[10] = 'x';
    //m[30] = 'a';

    //map<int,char>::iterator it;
    //it = m.find(28);
    //if(it!=m.end())
    //{
    //   cout<<(*it).first<<":"<<(*it).second<<endl;
    //}
    //else
    //{
    //  cout<<"not find it"<<endl;
    //}


    /*-------------------------------------------*/
    //自定义的比较函数
    //map<int,char,myComp>m;
    //m[25] = 'm';
    //m[28] = 'k';
    //m[10] = 'x';
    //m[30] = 'a';

    //map<int,char,myComp>::iterator it;
    //for(it = m.begin();it!=m.end();it++)
    //{
    //    cout<<(*it).first<<":"<<(*it).second<<endl;
    //}


    /*------------------------------------------*/
    //另一种定义方法
    //map<Info,int>m;
    //Info info;
    //info.name = "Jack";
    //info.score = 60;
    //m[info] = 10;
    //info.name = "Peti";
    //info.score = 66.5;
    //m[info] = 30;
    //map<Info,int>::iterator it;
    //for(it = m.begin();it!=m.end();it++)
    //{
    //   cout<<(*it).second<<":";
    //   cout<<((*it).first).name<<" "<<((*it).first).score<<endl;
    //}

    /*------------------------------------------*/
    //用map实现数字分离
    //map<char,int>m;
    //m['0'] = 0;
    //m['1'] = 1;
    //m['2'] = 2;
    //m['3'] = 3;
    // m['4'] = 4;
    // m['5'] = 5;
    // m['6'] = 6;
    // m['7'] = 7;
    // m['8'] = 8;
    // m['9'] = 9;

    /*
    for(int j = 0;j < 10;j++)
    {
        m[0+'j'] = j;
    }
    */
    // string sa,sb;
    // sa = "6234";
    //int i;
    //int sum = 0;
    //for(i = 0;i < sa.length();i++)
    //{
    //   sum+=m[sa[i]];
    // }
    // cout<<"sum = "<<sum<<endl;


    /*--------------------------------------------*/
    //数字映射字符
    map<int ,char>m;
    m[0] = '0';
    m[1] = '1';
    m[2] = '2';
    m[3] = '3';
    m[4] = '4';
    m[5] = '5';
    m[6] = '6';
    m[7] = '7';
    m[8] = '8';
    m[9] = '9';

    /*
    for(int j = 0;j < 10;j++)
    {
        m[j] = '0'+j;
    }
    */
    int n = 7;
    string s="The number is";
    cout<<s+m[n]<<endl;






}