◆ 常用的排序算法：
1.1、合并（容器A(全部/部分)&容器B(全部/部分)==>容器C(全部/部分)，容器C中元素已经排好顺序），返回的值==>iteratorOutBegin.end()
iterator merge(iterator1Begin, iterator1And, iterator2Begin, iterator2End, iteratorOutBegin);
iterator merge(iterator1Begin, iterator1And, iterator2Begin, iterator2End, iteratorOutBegin, functor排序); // ZC: 这里的functor指定，排序的话采用何种方式
1.2、排序
void sort(iteratorBegin, iteratorEnd);
void sort(iteratorBegin, iteratorEnd, functor排序);
1.3、随机洗牌（shuffle是洗牌的意思）（记得初始化随机种子）
void random_shuffle(iteratorBeign, iteratorEnd);
// ZC: 下面的functor作用是，通过容器中某个元素(传入参数) 计算得到它在容器中的新的位置，然后与这个位置上的原来的元素进行位置交换
void random_shuffle(iteratorBeign, iteratorEnd, functor产生随机位置);
1.4、反转
void reverse(iteratorBegin, iteratorEnd);
1、
◆ 以下是排序和通用算法：提供元素排序策略
1.1、第6讲 PPT.25
◆ merge() : 合并两个有序序列，存放到另一个序列。
ZC: 最终得到的result容器里面的元素是经过有序的
ZC: 有两种参数格式，返回值是 iterator[ 该值==result容器.end() ]
ZC: VC6 测试代码 - 1：
1 #ifdef WIN32 2 #pragma warning (disable: 4786) 3 #endif 4 5 #include <vector> 6 #include <set> 7 8 #include <algorithm> // 算法 9 #include <numeric> // 算法 10 #include <functional> // 算法 11 12 using namespace std; 13 14 void main() 15 { 16 vector<int> vecIntA; 17 vecIntA.push_back(1); 18 vecIntA.push_back(3); 19 vecIntA.push_back(5); 20 vecIntA.push_back(7); 21 vecIntA.push_back(9); 22 23 vector<int> vecIntB; 24 vecIntB.push_back(2); 25 vecIntB.push_back(4); 26 vecIntB.push_back(6); 27 vecIntB.push_back(8); 28 29 vector<int> vecIntC; 30 vecIntC.resize(9); // 扩大容量 // ZC: 如果不做这一步，VC6编译的exe就崩溃了 31 merge( 32 vecIntA.begin(), vecIntA.end(), 33 vecIntB.begin(), vecIntB.end(), 34 vecIntC.begin()); 35 vector<int>::iterator it = vecIntC.begin(); 36 // ZC: 从这里打印的信息来看，它自动做了排序处理 37 int iIdx = 0; 38 while (it != vecIntC.end()) 39 { 40 printf("[%02d] ==> *it : %d ", iIdx, *it); 41 it ++; 42 iIdx ++; 43 } 44 }
ZC：控制台输出 - 1：
1 [00] ==> *it : 1 2 [01] ==> *it : 2 3 [02] ==> *it : 3 4 [03] ==> *it : 4 5 [04] ==> *it : 5 6 [05] ==> *it : 6 7 [06] ==> *it : 7 8 [07] ==> *it : 8 9 [08] ==> *it : 9 10 Press any key to continue
ZC: VC6 测试代码 - 2：
来自msdn的例子（https://msdn.microsoft.com/en-us/library/9ew9xdb2(v=vs.80).aspx）
1 // alg_merge.cpp 2 // compile with: /EHsc 3 #include <vector> 4 #include <algorithm> 5 #include <functional> // For greater<int>( ) 6 #include <iostream> 7 8 // Return whether modulus of elem1 is less than modulus of elem2 9 bool mod_lesser ( int elem1, int elem2 ) 10 { 11 if (elem1 < 0) 12 elem1 = - elem1; 13 if (elem2 < 0) 14 elem2 = - elem2; 15 return elem1 < elem2; 16 } 17 18 int main() 19 { 20 using namespace std; 21 vector <int> v1a, v1b, v1 ( 12 ); 22 vector <int>::iterator Iter1a, Iter1b, Iter1; 23 24 // Constructing vector v1a and v1b with default less than ordering 25 int i; 26 for ( i = 0 ; i <= 5 ; i++ ) 27 v1a.push_back( i ); 28 29 int ii; 30 for ( ii =-5 ; ii <= 0 ; ii++ ) 31 v1b.push_back( ii ); 32 33 cout << "Original vector v1a with range sorted by the " 34 << "binary predicate less than is v1a = ( " ; 35 for ( Iter1a = v1a.begin( ) ; Iter1a != v1a.end( ) ; Iter1a++ ) 36 cout << *Iter1a << " "; 37 cout << ")." << endl; 38 39 cout << "Original vector v1b with range sorted by the " 40 << "binary predicate less than is v1b = ( " ; 41 for ( Iter1b = v1b.begin ( ) ; Iter1b != v1b.end ( ) ; Iter1b++ ) 42 cout << *Iter1b << " "; 43 cout << ")." << endl; 44 45 // Constructing vector v2 with ranges sorted by greater 46 vector <int> v2a ( v1a ) , v2b ( v1b ) , v2 ( v1 ); 47 vector <int>::iterator Iter2a, Iter2b, Iter2; 48 sort ( v2a.begin ( ) , v2a.end ( ) , greater<int> ( ) ); 49 sort ( v2b.begin ( ) , v2b.end ( ) , greater<int> ( ) ); 50 51 cout << "Original vector v2a with range sorted by the " 52 << "binary predicate greater is v2a = ( " ; 53 for ( Iter2a = v2a.begin ( ) ; Iter2a != v2a.end ( ) ; Iter2a++ ) 54 cout << *Iter2a << " "; 55 cout << ")." << endl; 56 57 cout << "Original vector v2b with range sorted by the " 58 << "binary predicate greater is v2b = ( " ; 59 for ( Iter2b = v2b.begin ( ) ; Iter2b != v2b.end ( ) ; Iter2b++ ) 60 cout << *Iter2b << " "; 61 cout << ")." << endl; 62 63 // Constructing vector v3 with ranges sorted by mod_lesser 64 vector <int> v3a ( v1a ), v3b ( v1b ) , v3 ( v1 ); 65 vector <int>::iterator Iter3a, Iter3b, Iter3; 66 sort ( v3a.begin ( ) , v3a.end ( ) , mod_lesser ); 67 sort ( v3b.begin ( ) , v3b.end ( ) , mod_lesser ); 68 69 cout << "Original vector v3a with range sorted by the " 70 << "binary predicate mod_lesser is v3a = ( " ; 71 for ( Iter3a = v3a.begin ( ) ; Iter3a != v3a.end ( ) ; Iter3a++ ) 72 cout << *Iter3a << " "; 73 cout << ")." << endl; 74 75 cout << "Original vector v3b with range sorted by the " 76 << "binary predicate mod_lesser is v3b = ( " ; 77 for ( Iter3b = v3b.begin ( ) ; Iter3b != v3b.end ( ) ; Iter3b++ ) 78 cout << *Iter3b << " "; 79 cout << ")." << endl; 80 81 // To merge inplace in ascending order with default binary 82 // predicate less <int> ( ) 83 merge ( v1a.begin ( ) , v1a.end ( ) , v1b.begin ( ) , v1b.end ( ) , v1.begin ( ) ); 84 cout << "Merged inplace with default order, vector v1mod = ( " ; 85 for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ ) 86 cout << *Iter1 << " "; 87 cout << ")." << endl; 88 89 // To merge inplace in descending order, specify binary 90 // predicate greater<int>( ) 91 merge ( v2a.begin ( ) , v2a.end ( ) , v2b.begin ( ) , v2b.end ( ) , 92 v2.begin ( ) , greater <int> ( ) ); 93 cout << "Merged inplace with binary predicate greater specified, " 94 << "vector v2mod = ( " ; 95 for ( Iter2 = v2.begin( ) ; Iter2 != v2.end( ) ; Iter2++ ) 96 cout << *Iter2 << " "; 97 cout << ")." << endl; 98 99 // Applying A user-defined (UD) binary predicate mod_lesser 100 vector <int>::iterator itRtn = merge ( v3a.begin ( ) , v3a.end ( ) , v3b.begin ( ) , v3b.end ( ) , 101 v3.begin ( ) , mod_lesser ); 102 cout << "Merged inplace with binary predicate mod_lesser specified, " 103 << "vector v3mod = ( " ; ; 104 for ( Iter3 = v3.begin( ) ; Iter3 != v3.end( ) ; Iter3++ ) 105 cout << *Iter3 << " "; 106 cout << ")." << endl; 107 108 itRtn --; 109 itRtn --; 110 cout << "*itRtn : " << *itRtn; 111 }
ZC：控制台输出 - 2 (vs2010)：
1 Original vector v1a with range sorted by the 2 binary predicate less than is v1a = ( 0 1 2 3 4 5 ). 3 Original vector v1b with range sorted by the 4 binary predicate less than is v1b = ( -5 -4 -3 -2 -1 0 ). 5 Original vector v2a with range sorted by the 6 binary predicate greater is v2a = ( 5 4 3 2 1 0 ). 7 Original vector v2b with range sorted by the 8 binary predicate greater is v2b = ( 0 -1 -2 -3 -4 -5 ). 9 Original vector v3a with range sorted by the 10 binary predicate mod_lesser is v3a = ( 0 1 2 3 4 5 ). 11 Original vector v3b with range sorted by the 12 binary predicate mod_lesser is v3b = ( 0 -1 -2 -3 -4 -5 ). 13 Merged inplace with default order, 14 vector v1mod = ( -5 -4 -3 -2 -1 0 0 1 2 3 4 5 ). 15 Merged inplace with binary predicate greater specified, 16 vector v2mod = ( 5 4 3 2 1 0 0 -1 -2 -3 -4 -5 ). 17 Merged inplace with binary predicate mod_lesser specified, 18 vector v3mod = ( 0 0 1 -1 2 -2 3 -3 4 -4 5 -5 ). 19 *itRtn : 5 20 请按任意键继续. . .
1.2、第6讲 PPT.26
◆ sort() : 以默认升序的方式重新排列指定范围内的元素。若要改排序规则，可以输入比较函数。
ZC: 有两种参数格式，返回值是 void 。
ZC: VC6 测试代码 - 1：
1 #ifdef WIN32 2 #pragma warning (disable: 4786) 3 #endif 4 5 #include <vector> 6 #include <set> 7 8 #include <algorithm> // 算法 9 #include <numeric> // 算法 10 #include <functional> // 算法 11 12 using namespace std; 13 14 void main() 15 { 16 vector<int> vecInt; 17 vecInt.push_back(1); 18 vecInt.push_back(30); 19 vecInt.push_back(5); 20 vecInt.push_back(17); 21 vecInt.push_back(9); 22 23 sort(vecInt.begin(), vecInt.end()); 24 25 vector<int>::iterator it = vecInt.begin(); 26 // ZC: 从这里打印的信息来看，它自动做了排序处理 27 int iIdx = 0; 28 while (it != vecInt.end()) 29 { 30 printf("[%02d] ==> *it : %d ", iIdx, *it); 31 it ++; 32 iIdx ++; 33 } 34 }
ZC：控制台输出 - 1：
1 [00] ==> *it : 1 2 [01] ==> *it : 2 3 [02] ==> *it : 3 4 [03] ==> *it : 4 5 [04] ==> *it : 5 6 [05] ==> *it : 6 7 [06] ==> *it : 7 8 [07] ==> *it : 8 9 [08] ==> *it : 9 10 Press any key to continue
ZC: VC6 测试代码 - 2：
1 #ifdef WIN32 2 #pragma warning (disable: 4786) 3 #endif 4 5 #include <string> 6 #include <vector> 7 #include <set> 8 9 #include <algorithm> // 算法 10 #include <numeric> // 算法 11 #include <functional> // 算法 12 13 using namespace std; 14 15 //学生类 16 class CStudent 17 { 18 public: 19 CStudent(int iID, string strName) 20 { 21 m_iID=iID; 22 m_strName=strName; 23 } 24 public: 25 int m_iID; 26 string m_strName; 27 }; 28 29 //学号比较函数 30 bool Compare(const CStudent &stuA, const CStudent &stuB) 31 { 32 return (stuA.m_iID < stuB.m_iID); 33 } 34 35 void main() 36 { 37 vector<CStudent> vecStu; 38 vecStu.push_back(CStudent(2, "老二")); 39 vecStu.push_back(CStudent(1, "老大")); 40 vecStu.push_back(CStudent(3, "老三")); 41 vecStu.push_back(CStudent(4, "老四")); 42 43 sort(vecStu.begin(), vecStu.end(), Compare); 44 // 此时，vecStu容器包含了按顺序的"老大对象","老二对象","老三对象","老四对象" 45 46 vector<CStudent>::iterator it = vecStu.begin(); 47 while (it != vecStu.end()) 48 { 49 printf("%s ", it->m_strName.c_str()); 50 it ++; 51 } 52 }
ZC：控制台输出 - 2：
1 老大 2 老二 3 老三 4 老四 5 Press any key to continue
1.3、第6讲 PPT.30
◆ random_shuffle() : 对指定范围内的元素随机调整次序。
ZC: 有两种参数格式，返回值是 void
ZC: VC6 测试代码 - 1：
1 #ifdef WIN32 2 #pragma warning (disable: 4786) 3 #endif 4 5 #include <time.h> 6 7 #include <string> 8 #include <vector> 9 #include <set> 10 11 #include <algorithm> // 算法 12 #include <numeric> // 算法 13 #include <functional> // 算法 14 15 using namespace std; 16 17 void main() 18 { 19 //设置随机种子 20 srand(time(0)); 21 22 vector<int> vecInt; 23 vecInt.push_back(1); 24 vecInt.push_back(3); 25 vecInt.push_back(5); 26 vecInt.push_back(7); 27 vecInt.push_back(9); 28 29 string str("UIPower"); 30 31 random_shuffle(vecInt.begin(), vecInt.end()); //随机排序，结果比如：9,7,1,5,3 32 random_shuffle(str.begin(), str.end()); //随机排序，结果比如："owreUIP" 33 34 vector<int>::iterator it = vecInt.begin(); 35 int iIdx = 0; 36 while (it != vecInt.end()) 37 { 38 printf("[%02d] ==> %d ", iIdx, *it); 39 it ++; 40 } 41 42 printf("str : %s ", str.c_str()); 43 }
ZC：控制台输出 - 1：
1 [00] ==> 9 2 [00] ==> 1 3 [00] ==> 3 4 [00] ==> 5 5 [00] ==> 7 6 str : IroePUw 7 Press any key to continue
ZC: VC6 测试代码 - 2（来自：http://www.cplusplus.com/reference/algorithm/random_shuffle/）：
1 // random_shuffle example 2 #include <iostream> // std::cout 3 #include <algorithm> // std::random_shuffle 4 #include <vector> // std::vector 5 #include <ctime> // std::time 6 #include <cstdlib> // std::rand, std::srand 7 8 // random generator function: 9 int myrandom (int i) 10 { 11 int iRand = std::rand(); 12 int iRtn = iRand % i; 13 printf("%d %% %d ==> %d ", iRand, i, iRtn); 14 return iRtn; 15 16 //return std::rand()%i; 17 } 18 19 int main () { 20 std::srand ( unsigned ( std::time(0) ) ); 21 std::vector<int> myvector; 22 23 // set some values: 24 for (int i=1; i<10; ++i) myvector.push_back(i); // 1 2 3 4 5 6 7 8 9 25 26 // using built-in random generator: // ZC: built-in ==> 内置 27 //std::random_shuffle ( myvector.begin(), myvector.end() ); // ZC: 先把这句代码注释掉，暂时只关注自定义的随机生成函数 28 29 // using myrandom: 30 std::random_shuffle ( myvector.begin(), myvector.end(), myrandom); 31 32 printf(" "); 33 34 // print out content: 35 std::cout << "myvector contains:"; 36 for (std::vector<int>::iterator it=myvector.begin(); it!=myvector.end(); ++it) 37 std::cout << ' ' << *it; 38 39 std::cout << ' '; 40 41 system("pause"); 42 return 0; 43 }
ZC：控制台输出 - 2：
1 4094 % 2 ==> 0 2 3749 % 3 ==> 2 3 18714 % 4 ==> 2 4 6449 % 5 ==> 4 5 634 % 6 ==> 4 6 29214 % 7 ==> 3 7 14374 % 8 ==> 6 8 8421 % 9 ==> 6 9 10 myvector contains: 2 1 4 7 6 5 9 3 8 11 请按任意键继续. . .
ZC：我理解的自定义随机函数变换方式：
1 2 3 4 5 6 7 8 9 原来的顺序（对于第0个元素 不做随机运算）
2 1 3 4 5 6 7 8 9 第1个元素(数字"2") 和 第0个元素 交换位置之后的结果
2 1 3 4 5 6 7 8 9 第2个元素(数字"3") 和 第2个元素 交换位置之后的结果(位置都没动)
2 1 4 3 5 6 7 8 9 第3个元素(数字"4") 和 第2个元素 交换位置之后的结果
2 1 4 3 5 6 7 8 9 第4个元素(数字"5") 和 第4个元素 交换位置之后的结果(位置都没动)
2 1 4 3 6 5 7 8 9 第5个元素(数字"6") 和 第4个元素 交换位置之后的结果
2 1 4 7 6 5 3 8 9 第6个元素(数字"7") 和 第3个元素 交换位置之后的结果
2 1 4 7 6 5 8 3 9 第7个元素(数字"8") 和 第6个元素 交换位置之后的结果
2 1 4 7 6 5 9 3 8 第8个元素(数字"9") 和 第6个元素 交换位置之后的结果
1.4、第6讲 PPT.30
◆ reverse() : 对指定范围内元素重新反序排序。
ZC: 只有一种参数格式，返回值是 void
ZC: VC6 测试代码：
1 #ifdef WIN32 2 #pragma warning (disable: 4786) 3 #endif 4 5 #include <string> 6 #include <vector> 7 #include <set> 8 9 #include <algorithm> // 算法 10 #include <numeric> // 算法 11 #include <functional> // 算法 12 13 using namespace std; 14 15 void main() 16 { 17 vector<int> vecInt; 18 vecInt.push_back(1); 19 vecInt.push_back(3); 20 vecInt.push_back(5); 21 vecInt.push_back(7); 22 vecInt.push_back(9); 23 24 reverse(vecInt.begin(), vecInt.end()); //{9,7,5,3,1} 25 26 vector<int>::iterator it = vecInt.begin(); 27 int iIdx = 0; 28 while (it != vecInt.end()) 29 { 30 printf("[%02d] ==> %d ", iIdx, *it); 31 it ++; 32 } 33 }
ZC：控制台输出：
1 [00] ==> 9 2 [00] ==> 7 3 [00] ==> 5 4 [00] ==> 3 5 [00] ==> 1 6 Press any key to continue
?.?、第6讲 PPT.?
◆
ZC: VC6 测试代码：
ZC：控制台输出：
C