Algorithm学习之all_of学习

all_of

Visual Studio 2010

 

 

Returns true when a condition is present at each element in the given range.

 当所有在指定的范围内所有元素都满足指定条件的时候返回true。

template<class InputIterator, class Predicate>

    bool all_of(

        InputIterator _First, 

        InputIterator _Last, 

        BinaryPredicate _Comp

    );

 

Parameters

_First

An input iterator that indicates where to start to check for a condition. The iterator marks where a range of elements starts.

起始搜索地址。

_Last

An input iterator that indicates the end of the range of elements to check for a condition.

结束搜索地址。

_Comp

A condition to test for. This is a user-defined predicate function object that defines the condition to be satisfied by an element being checked. A predicate takes a single argument and returns true or false.

给定条件。只有一个参数，返回值为true或false。

 

Return Value

Returns true if the condition is detected at each element in the indicated range, and false if the condition is not detected at least one time.

当指定范围内所有元素都满足条件时就返回true，当有至少一个元素不满足条件时返回false。

Remarks

The template function returns true only if, for each N in the range [0, _Last - _First), the predicate _Comp(*(_First + N)) is true.

模板函数只有当对于范围内的N个数都满足给定条件的时候返回true。

Requirements

Header: <algorithm>

Namespace: std

 

程序示例：

 1 // all_of.cpp : 定义控制台应用程序的入口点。

 2 //

 3 

 4 #include "stdafx.h"

 5 #include <algorithm>

 6 #include <list>

 7 #include <iostream>

 8 #include <vector>

 9 using namespace std;

10 

11 bool IsEven( int elem ) 

12 {

13     if( elem%2 == 0 )

14         return true;

15     else

16         return false;

17 }

18 

19 int _tmain(int argc, _TCHAR* argv[])

20 {

21     

22     list <int> L;

23     

24     L.push_back(2);

25     L.push_back(4);

26     L.push_back(6);

27     L.push_back(8);

28     L.push_back(10);

29 

30     if( all_of( L.begin(), L.end(), IsEven ) )

31         cout << " Yes,all the elements in the list are even! " << endl;

32     else

33         cout << " No,some of the elements in the list are not even! " << endl;

34     

35     int arr1[5] = {1,2,4,6,8};

36     vector<int> v1(arr1,arr1+5);

37     if( all_of( v1.begin( ), v1.end( ), IsEven ) )

38         cout << " Yes,all the elements in the vector are even! " << endl;

39     else

40         cout << " No,some of the elements in the vector are not even! " << endl;

41 

42     int arr[5] = {1,2,3,4,5};

43     if( all_of( arr, arr+5, IsEven ) )

44         cout << " Yes,all the elements in the array are even! " << endl;

45     else

46         cout << " No,some of the elements in the array are not even! " << endl;

47 

48     system("pause");

49 }

程序运行结果截图：