28.数值算法小结

#include <vector>
#include <list>
#include <algorithm>
#include <iostream>
using namespace std;

void main()
{
    //拷贝数据,与反向拷贝
    {
        vector<int> myint{ 1,2,3,4,5 };
        list<int> mylist{ 6,7,8,9,10 };
        //指定长度进行拷贝(注意,不会把容器长度增长)
        /*copy(myint.begin(), myint.end()-2, mylist.begin());*/
        //从尾部到头部进行拷贝(反向拷贝)
        copy_backward(myint.begin(), myint.end(), mylist.end());
        for (auto i : mylist)
        {
            cout << i << endl;
        }
    }
    
    //交换数据
    {
        double a = 10;
        double b = 20;
        swap(a, b);
        cout << a << b << endl;
    }
    
    //交换容器
    {
        vector<int> myint{ 1,2,3,4 };
        vector<int> mynewint{ 6,7,8,9 };
        list<int> mylist{ 1,2,3,9 };
        swap(myint, mynewint);//交换数据
        //类型不一致,不允许交换数据
        //swap(myint,mylist);
    }

    //交换指针
    {
        int a = 5;
        int b = 10;
        //交换指针的地址
        iter_swap(&a, &b);
        cout << a << b << endl;
    }

    //交换容器中的两个数据
    {
        vector<int> myint{ 1,2,3,4,5 };

        iter_swap(myint.begin(), myint.begin() + 2);
        for (auto i : myint)
        {
            cout << i << endl;
        }
    }

    //交换两个容器间的一部分
    {
        vector<int> myint1{ 1,2,3,4 };
        vector<int> myint2{ 6,7,8,9 };
        //交换部分
        swap_ranges(myint1.begin(), myint1.begin() + 2, myint2.begin() + 2);

        for (auto i : myint2)
        {
            cout << i << endl;
        }
    }

    //批量修改容器中的元素
    {
        vector<int> myint{ 1,2,3,4,5 };
        transform(myint.begin(), myint.end(), myint.begin(), [](int x) {return x * x; });
        for (auto i : myint)
        {
            cout << i << endl;
        }
    }

    //批量替换
    {
        vector<int> myint{ 1,2,3,4,5,1,2,3,4 };
        replace(myint.begin(), myint.end(), 3, 300);
        for (auto i : myint)
        {
            cout << i << endl;
        }
    }

    //根据条件全部替换
    {
        vector<int> myint{ 1,2,3,4,5,1,2,3,4 };
        replace_if(myint.begin(), myint.end(), [](int x)->bool {return x % 2; }, 0);
        for (auto i : myint)
        {
            cout << i << endl;
        }
    }

    //批量替换到副本中
    {
        vector<int> myint{ 1,2,3,4,5,1,2,3,4 };
        vector<int> myintlast{ 0,0,0,0,0,0,0,0,0 };
        replace_copy(myint.begin(), myint.end(), myintlast.begin(), 3, 300);
        for (auto i : myintlast)
        {
            cout << i << endl;
        }
    }

    //根据条件全部替换到副本中
    {
        vector<int> myint{ 1,2,3,4,5,1,2,3,4 };
        vector<int> myintlast{ 0,0,0,0,0,0,0,0,0 };
        replace_copy_if(myint.begin(), myint.end(), myintlast.begin(), [](int x)->bool {return x % 2; }, 0);
        for (auto i : myintlast)
        {
            cout << i << endl;
        }
    }
    
    //填充一个容器
    {
        vector<int> myint{ 1,2,3,4,5,1,2,3,4 };
        vector<int> myintlast{ 0,0,0,0,0,0,0,0,0 };
        fill(myintlast.begin(), myintlast.end(), 199);

        fill_n(myint.begin(), 3, 100);
        for (auto i : myintlast)
        {
            cout << i << endl;
        }

        for (auto i : myint)
        {
            cout << i << endl;
        }
    }

    //删除容器中指定的数据(不是彻底删除,删除后从后往前移动)
    {
        vector<int> myint{ 1,2,3,4,5,1,2,3,4 };
        vector<int> myintlast{ 0,0,0,0,0,0,0,0,0 };

        //it保存最后一个元素的位置
        auto it = remove(myint.begin(), myint.end(), 3);
        //此种方式会显示后面的空间的数据
        /*for (auto i : myint)
        {
            cout << i << endl;
        }*/
        for (auto ib = myint.begin(); ib != it; ib++)
        {
            cout << *ib << endl;
        }
    }

    //删除容器中满足条件的数据(不是彻底删除,删除后从后往前移动)
    {
        vector<int> myint{ 1,2,3,4,5,1,2,3,4 };
        vector<int> myintlast{ 0,0,0,0,0,0,0,0,0 };

        //it保存最后一个元素的位置
        auto it = remove_if(myint.begin(), myint.end(), [](int x)->bool {return x % 2; });
        //此种方式会显示后面的空间的数据
        /*for (auto i : myint)
        {
        cout << i << endl;
        }*/
        for (auto ib = myint.begin(); ib != it; ib++)
        {
            cout << *ib << endl;
        }
    }

    //对副本进行删除
    {
        vector<int> myint{ 1,2,3,4,5,1,2,3,4 };
        vector<int> myintlast;
        for (int i = 0; i < 9; i++)
        {
            myintlast.push_back(0);
        }

        remove_copy(myint.begin(), myint.end(), myintlast.begin(), 3);
        for (auto i : myintlast)
        {
            cout << i << endl;
        }
        
    }

    //拷贝的时候删除连续重复的
    {
        vector<int> myint{ 1,2,3,4,5,1,2,3,4 };
        unique(myint.begin(), myint.end());
        for (auto i : myint)
        {
            cout << i << endl;
        }
    }

    //拷贝的时候删除连续重复的(对副本)
    {
        vector<int> myint{ 1,2,3,4,5,1,2,3,4 };
        int a[9]{ 0 };
        unique_copy(myint.begin(), myint.end(), a);
        for (auto i : a)
        {
            cout << i << endl;
        }
    }

    //容器反转
    {
        vector<int> myint{ 1,2,3,4,5,1,2,3,4 };
        reverse(myint.begin(), myint.end());
        for (auto i : myint)
        {
            cout << i << endl;
        }
    }

    

    //区间交换到副本中
    {
        vector<int> myint{ 1,2,3,4,5,6,7,8,9 };
        rotate(myint.begin(), myint.begin() + 4, myint.end());
        for (auto i : myint)
        {
            cout << i << endl;
        }
    }
    
    //区间交换
    {
        vector<int> myint{ 1,2,3,4,5,6,7,8,9 };
        int a[9]{ 0 };
        //begin取数组的头结点
        rotate_copy(myint.begin(), myint.begin() + 4, myint.end(), begin(a));
        for (auto i : a)
        {
            cout << i << endl;
        }
    }

    //洗牌算法
    {
        vector<int> myint{ 1,2,3,4,5,6,7,8,9 };
        random_shuffle(myint.begin(), myint.end());
        for (auto i : myint)
        {
            cout << i << endl;
        }
    }

    //根据条件进行分段(例如小的在左边,大的在右边)   (相对顺序会发生变化)
    {
        vector<int> myint{ 1,9,2,8,3,7,4,6,5,10 };
        //it的位置是分界点
        auto it = partition(myint.begin(), myint.end(), [](int x)->int {return x <= 5 ? 1 : 0; });
        for (auto i : myint)
        {
            cout << i << endl;
        }
    }

    //根据条件进行分段(对副本进行操作)(例如小的在一个容器,大的在一个容器)   (相对顺序会发生变化)
    {
        vector<int> myint{ 1,9,2,8,3,7,4,6,5,10 };
        vector<int> myintX{ 0,0,0,0,0,0,0,0,0,0 };
        vector<int> myintY{ 0,0,0,0,0,0,0,0,0,0 };
        
        //两段分别拷贝到两个容器
        auto it = partition_copy(myint.begin(), myint.end(),myintX.begin(),myintY.begin(), [](int x)->int {return x <= 5 ? 1 : 0; });
        for (auto i : myintX)
        {
            cout << i << endl;
        }

        for (auto i : myintY)
        {
            cout << i << endl;
        }
    }

    //根据条件进行分段(例如小的在左边,大的在右边)   (相对顺序不发生变化)
    {
        vector<int> myint{ 1,9,2,8,3,7,4,6,5,10 };
        //it的位置是分界点
        auto it = stable_partition(myint.begin(), myint.end(), [](int x)->int {return x <= 5 ? 1 : 0; });
        for (auto i : myint)
        {
            cout << i << endl;
        }
    }

    //填充
    {
        vector<int> myint(10);
        //指定数据填充
        generate(myint.begin(), myint.end(), []() {return 10; });
        //随机数填充
        generate(myint.begin(), myint.end(), rand);
        //指定位置填充n个
        generate_n(myint.begin()+2, 3, rand);
        for (auto i : myint)
        {
            cout << i << endl;
        }

    }

    cin.get();
}