C++ //常用集合算法 //set_intersection //求俩个容器的交集 //set_union //求两个容器的并集 //set_difference //求两个容器的差集

  1 //常用集合算法
  2 //set_intersection   //求俩个容器的交集
  3 //set_union          //求两个容器的并集
  4 //set_difference    //求两个容器的差集
  5
  6 #include<iostream>
  7 #include<vector>
  8 #include<algorithm>
  9 using namespace std;
 10
 11
 12 void myprint(int v)
 13 {
 14     cout << v << " ";
 15 }
 16 //set_intersection   //求俩个容器的交集  (必须是有序序列)
 17 void test01()
 18 {
 19     vector<int>v1;
 20     vector<int>v2;
 21
 22
 23     for (int i = 0; i < 10; i++)
 24     {
 25         v1.push_back(i);    //0 -9
 26         v2.push_back(i + 5); //5-14
 27     }
 28
 29     vector<int>vTarget;
 30     //目标容器需要提前开辟空间.
 31     //最特殊的情况  大容器包含小容器 开辟空间 取小容器的size
 32     vTarget.resize(min(v1.size(), v2.size()));
 33
 34     //获取交际
 35     vector<int>::iterator itEnd=set_intersection(v1.begin(), v1.end(), v2.begin(), v2.end(), vTarget.begin());
 36
 37     for_each(vTarget.begin(), itEnd, myprint);
 38     cout << endl;
 39
 40 }
 41
 42 //set_union  并集  有序序列
 43
 44 class MyPrint
 45 {
 46 public:
 47
 48     void operator()(int l)
 49     {
 50         cout << l << " ";
 51     }
 52 };
 53
 54
 55 void test02()
 56 {
 57     vector<int>v1;
 58     vector<int>v2;
 59
 60     for (int i = 0; i < 10; i++)
 61     {
 62         v1.push_back(i);
 63         v2.push_back(i + 5);
 64     }
 65
 66     vector<int>vTarget;
 67     //最特殊的情况是 没有交集   并集两个容器相加
 68     vTarget.resize(v1.size()+v2.size());
 69
 70     vector<int>::iterator itEnd=set_union(v1.begin(), v1.end(), v2.begin(), v2.end(), vTarget.begin());
 71     for_each(vTarget.begin(), itEnd, MyPrint());
 72     cout << endl;
 73
 74 }
 75
 76 //set_difference    //求两个容器的差集
 77 void myPrint(int vc)
 78 {
 79     cout << vc << " ";
 80 }
 81 void test03()
 82 {
 83     vector<int>v1;
 84     vector<int>v2;
 85
 86     for (int i = 0; i < 10; i++)
 87     {
 88         v1.push_back(i);
 89         v2.push_back(i + 5);
 90     }
 91
 92     //差集放到目标容器中
 93     //最特殊的情况  两个容器没有交集 取大的空间
 94     vector<int>vTarget;
 95     vTarget.resize(max(v1.size(), v2.size()));
 96
 97     cout << "V1和V2的差集" << endl;
 98     vector<int>::iterator Itend = set_difference(v1.begin(), v1.end(), v2.begin(), v2.end(), vTarget.begin());
 99
100
101     for_each(vTarget.begin(), Itend, myPrint);
102     cout << endl;
103
104     cout << "V2和V1的差集" << endl;
105     Itend = set_difference(v2.begin(), v2.end(), v1.begin(), v1.end(), vTarget.begin());
106
107     for_each(vTarget.begin(), Itend, myPrint);
108     cout << endl;
109
110 }
111
112 int main()
113 {
114     test01();
115
116     test02();
117
118     test03();
119     system("pause");
120     return 0;
121 }