轉自：http://www.cnblogs.com/graphics/archive/2010/06/01/1749569.html

簡介

set是一種隨機存儲的關聯式容器，其關鍵詞（key）和元素（value）是同一個值。set之中所有元素互不相同。set是通過二叉查找樹來實現的。

創建

創建一個空的set

  1: set<> s0 ;

創建一個帶大於比較器的set, 默認是小於比較器less<int>

  1: set<, greater<>> s1 ;

用數組初始化一個set

  1:  a[3] = {1, 2, 3} ;

  2: set<> s2(a, a + 3) ;

用拷貝構造函數初始化set

  1: set<> s1 ;

  2: set<> s2(s1) ;

區間初始化

  1: set<> s1 ;

  2: set<> s2(s1.begin(), s1.end()) ;

自定義比較函數

以類為比較器

  1:  classcmp

  2: {

  3:    ()( & lhs,  & rhs)

  4:   {

  5:      lhs < rhs ;

  6:   }

  7: };

  8: 

  9:  main()

 10: {

 11:   set<, classcmp> s5 ;

 12: 

 13:   system("") ;

 14:    0 ;

 15: }

以函數指針為比較器

  1:  fncmp( lhs,  rhs)

  2: {

  3:    lhs < rhs ;

  4: }

  5: 

  6:  main()

  7: {

  8:   (*fn_pt)(, ) = fncmp ;

  9:   set<, (*)(, )> s1(fn_pt) ;

 10: 

 11:   system("") ;

 12:    0 ;

 13: }

 

遍歷

正向遍歷

使用while

  1:  a[3] = {1, 2, 3} ;

  2: set<> s(a, a + 3) ;

  3: 

  4: set<>::const_iterator itor ;

  5: itor = s.begin() ;

  6: 

  7:  (itor != s.end())

  8: {

  9:   cout << *itor << endl ;

 10:   ++itor ;

 11: }

使用for

  1:  a[3] = {1, 2, 3} ;

  2: set<> s(a, a + 3) ;

  3: 

  4: set<>::const_iterator itor ;

  5:  (itor = s.begin(); itor != s.end(); ++itor)

  6: {

  7:   cout << *itor << endl ;

  8: }

 

反向遍歷

使用while

  1:  a[3] = {1, 2, 3} ;

  2: set<> s(a, a + 3) ;

  3: 

  4: set<>::const_reverse_iterator ritor ;

  5: ritor = s.rbegin() ;

  6: 

  7:  (ritor != s.rend())

  8: {

  9:   cout << *ritor << endl ;

 10:   ++ritor ;

 11: }

使用for

  1:  a[3] = {1, 2, 3} ;

  2: set<> s(a, a + 3) ;

  3: 

  4: set<>::const_reverse_iterator ritor ;

  5:  (ritor = s.rbegin(); ritor != s.rend(); ++ritor)

  6: {

  7:   cout << *ritor << endl ;

  8: }

插入

插入單個值

  1: set<> s ;

  2: s.insert(1) ;

成片插入

插入整個數組

  1:  a[3] = {1, 2, 3} ;

  2: set<> s ;

  3: s.insert(a, a + 3) ;

插入其他set的值

  1:  a[3] = {1, 2, 3} ;

  2: set<> s(a, a + 3) ;

  3: 

  4: set<> s1 ;

  5: s1.insert(s.begin(), s.end()) ;

刪除

  1: set<> s ;

  2:  ( i = 1; i <= 5; ++i)

  3:   s.insert(i) ;

  4: 

  5: set<>::const_iterator citor ;

  6: citor = s.begin() ;

  7: ++citor ; 

  8: 

  9: 

 10: s.erase(citor) ; 

 11: 

 12: 

 13: citor = s.find(3) ; 

 14: s.erase(citor, s.end()) ; 

 15: 

 16: 

 17: s.erase(s.begin(), s.end()) ;

查找

find

  1: set<> s ;

  2:  ( i = 1; i <= 5; ++i)

  3:   s.insert(i) ;

  4: 

  5: set<>::iterator itor ;

  6: itor = s.find(4) ;

  7: (itor != s.end()) 

  8:   cout << "" ;

  9: 

 10:   cout << "" ;

count

  1: set<> s ;

  2:  ( i = 1; i <= 5; ++i)

  3:   s.insert(i) ;

  4: 

  5: set<>::iterator itor ;

  6: (s.count(4) == 1) 

  7:   cout << "" ;

  8: 

  9:   cout << "" ;

排序

由於set本身是有序的，所以不提供排序函數。