STL之Map遍历

分手后的思念是犯贱 2022-10-27 12:20 320阅读 0赞

//默认顺序（从小到大）
    map<string, int > m1{  { "张三",10},{ "李四",20} };
    //从大到小排序
    map<string, int, greater<string> > m2{  { "张三",10},{ "李四",20} };
    //从小到大排序
    map<string, int, less<string> > m3{  { "张三",10},{ "李四",20} };

//定义遍历指针it
    map<string,int>::iterator it;
    for(it=m1.begin();it!=m1.end();it++)
    { 
    	cout<<(*it).first<<" "<<(*it).second<<endl;
    }

cout<<"简单遍历方法"<<endl;
    for(auto &it:m1)
    { 
    	cout<<it.first<<" "<<it.second<<endl;
    }

完整code：

#include<iostream>
    #include<algorithm>
    #include<cstring>
    #include<vector>
    #include<map>
    using namespace std;
    typedef long long ll;
    const ll N=1e6;
    map<string, int > m1{  { "张三",10},{ "李四",20} };
    map<string, int, greater<string> > m2{  { "张三",10},{ "李四",20} };
    map<string, int, less<string> > m3{  { "张三",10},{ "李四",20} };
    int main()
    { 
    	map<string,int>::iterator it;
    	cout<<"默认顺序"<<endl; 
    	for(it=m1.begin();it!=m1.end();it++)
    	{ 
    		cout<<(*it).first<<" "<<(*it).second<<endl;
    	} 
    	
    	cout<<endl;
    	cout<<"从大到小"<<endl;
    	for(it=m2.begin();it!=m2.end();it++)
    	{ 
    		cout<<(*it).first<<" "<<(*it).second<<endl;
    	} 
    	
    	cout<<endl;
    	cout<<"从小到大（就是默认顺序）"<<endl;
    	for(it=m3.begin();it!=m3.end();it++)
    	{ 
    		cout<<(*it).first<<" "<<(*it).second<<endl;
    	}  
    	
    	cout<<endl;
    	cout<<"简单遍历方法"<<endl;
    	for(auto &it:m1)
    	{ 
    		cout<<it.first<<" "<<it.second<<endl;
    	}
    	return 0;
     }

![SLT之Map遍历][SLT_Map]

[SLT_Map]: /images/20221024/4f20a83155ea4f74b4f021b261b06eec.png