Vector怎么对成员过滤啊？

[tangxu12]

Point3d 是一个点的类，有三个变量X Y Z分别代表点的坐标
Class Point3d
{
public:
double X;
double Y;
double Z;
}

vector <Point3d> MyPointList;

请问怎么把X+Y+Z>100的点过滤去来。

情况一：在原来的vector中把不符合要求的点 删除了。
情况二：把符合要求的点组成一个新的vector。

[red_berries]

1.遍历一遍，不合要求的erase()
2.insert

[mstlq]

可以用remove_if函数和erase函数

#include <vector>
#include <algorithm>
//#include <iostream>

class Point3d 
{ 
public: 
    double X; 
    double Y; 
    double Z; 
}; 

bool greater100 ( Point3d  p ) 
{
   return p.X+p.Y+p.Z >100;
};

int main( ) 
{
   using namespace std;
   vector <Point3d> MyPointList; 
  //在这里初始化MyPointList； 
  
  
   vector <Point3d>::iterator new_end; 
   new_end=remove_if(MyPointList.begin(),MyPointList.end(),greater100);
   MyPointList.erase (new_end, MyPointList.end( ) );
   return 0;
};

[T技术沙龙]

[Quote=引用 1 楼 red_berries 的回复:]
1.遍历一遍，不合要求的erase()
2.insert
[/Quote]
顶，vector这个部分学的不是很好

[Walf_ghoul]

#include <iostream>
#include <vector.h>

using namespace std;

class Point3d
{
   public:
        double x;
        double y;
        double z;

        Point3d(double x1,double y1,double z1)
        {
            x = x1;
            y = y1;
            z = z1;
        }
};

int main()
{
	vector<Point3d> MyPointList;
	vector<Point3d>::iterator it;
	Point3d* p1 = new Point3d(90,90,90); //建立三组数据作为测试数据
	Point3d* p2 = new Point3d(9,9,8);
	Point3d* p3 = new Point3d(90,9,0);
	MyPointList.push_back(*p1);
	MyPointList.push_back(*p2);
	MyPointList.push_back(*p3);
	for( it = MyPointList.begin();it != MyPointList.end();it++) //删除不符合条件的元素
	{
	    if((*it).x+(*it).y+(*it).z > 100)
	    {
	        MyPointList.erase(it);
	    }
	}
	for( it = MyPointList.begin();it != MyPointList.end();it++)//输出容器的内容
	{
	    cout<<it->x<<" "<<it->y<<" "<<it->z<<endl;
	}
	return 0;
}

结果：
9 9 8
90 9 0

Process returned 0 (0x0) execution time : 0.015 s
Press any key to continue.

[mstlq]

过滤代码2楼已经有了，这个是加入新vector的……

#include <algorithm>
#include <functional>
#include <iostream>
#include <vector>
using std::vector;

class Point3d 
{ 
public: 
    double X; 
    double Y; 
    double Z; 
}; 

void shows(Point3d p)
{
     std::cout<<p.X<<'\t'<<p.Y<<'\t'<<p.Z<<std::endl;
};

class insertIfGreater100
{
public:
    void operator()(Point3d p)
    {
        if (p.X+p.Y+p.Z <=100)
           PointList_.push_back(p);        
    };
    insertIfGreater100(vector <Point3d> &PointLis):PointList_(PointLis){};
private:
    vector <Point3d> &PointList_;        
};


int main( ) 
{
   using namespace std;
   vector <Point3d> MyPointList; 
   //shows sp;
  //在这里初始化MyPointList； 
   for(int i=3;i<200;i+=20)
   {
        Point3d tmp;
        tmp.X=i;
        tmp.Y=i;
        tmp.Z=i;
        MyPointList.push_back(tmp);
   }
   cout<<"MyPointList:"<<endl;
   for_each(MyPointList.begin(),MyPointList.end(),shows);
   
   vector <Point3d> MynewPointList;   
   MynewPointList.clear();
   
   insertIfGreater100 iig(MynewPointList);
   for_each(MyPointList.begin(),MyPointList.end(),iig);
   
   cout<<"----------------"<<endl<<"MynewPointList:"<<endl;  
   for_each(MynewPointList.begin(),MynewPointList.end(),shows);
   system("pause");
   return 0;
};

输出如下：
MyPointList:
3 3 3
23 23 23
43 43 43
63 63 63
83 83 83
103 103 103
123 123 123
143 143 143
163 163 163
183 183 183
----------------
MynewPointList:
3 3 3
23 23 23
请按任意键继续. . .

[lori227]

还是用stl 里的算法比较好~~

[winingsky]

帮顶！！