01串的排序问题_算法

01 串的排序问题：

Code:

//首先按长度排序，

//长度一样，按'1'的个数排序，

//‘1’的个数一样时，就按ASCII排序

#include <iostream>

#include <string>

#include <set>

#include <algorithm>

#include <fstream>

//if there is not included fstream libary ,we will get the bottom error:

///main.cpp|26|error: variable `std::ifstream cin' has initializer but incomplete type|

//||=== 完成的Build： 1 个错误, 0 个警告 ===|

using namespace std;

struct cmp//比较算法：从'1'的个数 按小到大排

{

//重载()操作

bool operator () (const string &s1,const string &s2)//返回1 ,0 ,-1

{

if(s1.length()!=s2.length())

return s1.length()<s2.length(); //返回比较长度的逻辑值

int c1 = count(s1.begin(),s1.end(),'1');

int c2 = count(s2.begin(),s2.end(),'1');

return (c1!=c2?c1<c2:s1<s2); //c1等于c2时返回c1<c2的逻辑值，否者返回ASCII值

}

};

int main(int argc,char *argv[])

{

multiset<string,cmp>ms;//Why choose multiset data struct in this place?

ifstream cin("aaa.txt");

string str;

while(cin>>str)

{

ms.insert(str);

}

multiset<string,cmp>::iterator iter;

for(iter=ms.begin();iter!=ms.end();iter++)

{

cout<<*iter<<endl;

}

return 0;

}