stl常用算法(Algorithms)介绍(stl排序算法、非变序型队列)

// 变序型队列算法

#include <iostream>
#include <algorithm>
#include <iterator>

//下面用到了输出迭代器ostream_iterator

using namespace std;

int main(void)
{   int arr0[6]= {1,12,3,2,1215,90};
    int arr1[7];
    int arr2[6]= {2,5,6,9,0,-56};

    //将数组aar复制到arr1
    copy(arr0,(arr0+6),arr1);

    cout<<"arr0[6] copy to arr1[7],now arr1: "<<endl;
    for(int i=0; i<7; i++)  
    cout<<" "<<arr1[i];

    //最后一个数组元素未赋值，因此输出内容为一随机数

    //将排好序的arr翻转

    reverse(arr0,arr0+6);
    cout<<"\n"<<"arr reversed ,now arr:"<<endl;

    //复制到输出迭代器
    copy(arr0,arr0+6,ostream_iterator<int>(cout, " "));

    //交换arr0和arr2序列

    swap_ranges(arr0,arr0+6,arr2);

    cout<<"\n"<<"arr0 swaped to arr2, and now arr0's content:"<<endl;
    copy(arr0,arr0+6,ostream_iterator<int>(cout, " "));

    cout<<"\n"<<"arr2:"<<endl;
    copy(arr2,arr2+6,ostream_iterator<int>(cout, " "));

    return 0;
}

// 非变序型队列算法

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

using namespace std;

int main(void)
{   int a[10]= {12,31,5,2,23,121,0,89,34,66};

    vector<int> v1(a,a+10);
    vector<int>::iterator result1,result2; //result1和result2是随机访问迭代器

    result1=find(v1.begin(),v1.end(),2); //在v1中找到2，result1指向v1中的2

    result2=find(v1.begin(),v1.end(),8); //在v1中没有找到8，result2指向的是v1.end()

    cout<<result1-v1.begin()<<endl;  //3－0＝3或4－1＝3，屏幕结果是3
    cout<<result2-v1.end()<<endl;  //10-10=0;

    int b[9]= {5,2,23,54,5,5,5,2,2};

    cout<<"a[10]={12,31,5,2,23,121,0,89,34,66};\n";
    cout<<"b[9]={5,2,23,54,5,5,5,2,2};\n";

    vector<int> v2(a+2,a+8);
    vector<int> v3(b,b+4);

    result1=search(v1.begin(),v1.end(),v2.begin(),v2.end());

    cout<<*result1<<endl;
    //在v1中找到了序列v2，result1指向v2在v1中开始的位置

    result1=search(v1.begin(),v1.end(),v3.begin(),v3.end());

    cout<<*(result1-1)<<endl;
    //在v1中没有找到序列v3，result指向v1.end(),屏幕打印出v1的最后一个元素66

    vector<int> v4(b,b+9);

    int i=count(v4.begin(),v4.end(),5);
    int j=count(v4.begin(),v4.end(),2);

    cout<<"there are "<<i<<" members in v4 equel to 5"<<endl;
    cout<<"there are "<<j<<" members in v4 equel to 2"<<endl;

    //计算v4中有多少个成员等于 5,2
    return 0;
}

//排序值算法

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

int main(void)
{   int a[10]= {12,0,5,3,6,8,9,34,32,18};
    int b[5]= {5,3,6,8,9};
    int d[15];

    sort(a,a+10);
    cout<<"Sorted a[10]:";
    for(int i=0; i<10; i++)
        cout<<a[i]<<" ";

    sort(b,b+5);  // 3 5 6 8 8

    if(includes(a,a+10,b,b+5))  //一个数组是否包含另外一个数组
        cout<<"\n"<<"sorted b members are included in a."<<endl;
    else
        cout<<"sorted a dosn`t contain sorted b!";

    merge(a,a+10,b,b+5,d); //合并

    cout<<"a[10]={12,0,5,3,6,8,9,34,32,18};\n";
    cout<<"b[5]={5,3,6,8,9};\n";
    cout<<"merge(a,a+10,b,b+5,d);\n ";
    cout<<"then d[15]:\n";
    for(int j=0; j<15; j++)
        cout<<d[j]<<" ";
    return 0;
}