c++11新增的便利算法实例分析

template< class InputIt, class UnaryPredicate >
bool all_of( InputIt first, InputIt last, UnaryPredicate p );

template< class InputIt, class UnaryPredicate >
bool any_of( InputIt first, InputIt last, UnaryPredicate p );

template< class InputIt, class UnaryPredicate >
bool none_of( InputIt first, InputIt last, UnaryPredicate p );

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main()
{
    vector<int> v = { 1, 3, 5, 7, 9 };
　　 auto isEven = [](int i){return i % 2 != 0;
    bool isallOdd = std::all_of(v.begin(), v.end(), isEven);
    if (isallOdd)
       cout << "all is odd" << endl;

    bool isNoneEven = std::none_of(v.begin(), v.end(), isEven);
    if (isNoneEven)
       cout << "none is even" << endl;

    vector<int> v1 = { 1, 3, 5, 7, 8, 9 };
    bool anyof = std::any_of(v1.begin(), v1.end(), isEven);
    if (anyof)
       cout << "at least one is even" << endl;
}

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

int main()
{
  vector<int> v = { 1, 3, 5, 7, 9,4 };
  auto isEven = [](int i){return i % 2 == 0;};
  auto firstEven = std::find_if(v.begin(), v.end(), isEven);
  if (firstEven!=v.end())
       cout << "the first even is " <<* firstEven << endl;

    //用find_if来查找奇数则需要重新写一个否定含义的判断式
　　auto isNotEven = [](int i){return i % 2 != 0;};
　　auto firstOdd = std::find_if(v.begin(), v.end(),isNotEven);

    if (firstOdd!=v.end())
       cout << "the first odd is " <<* firstOdd << endl;

    //用find_if_not来查找奇数则无需新定义判断式

    auto odd = std::find_if_not(v.begin(), v.end(), isEven);
    if (odd!=v.end())
       cout << "the first odd is " <<* odd << endl;
}

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

int main()
{
    vector<int> v = { 1, 3, 5, 7, 9, 4 };
    std::vector<int> v1(v.size());
　　　　//根据条件拷贝
　　　　auto it = std::copy_if(v.begin(), v.end(), v1.begin(), [](int i){return i%2!=0;});
　　　　//缩减vector到合适大小
  　　v1.resize(std::distance(v1.begin(),it));
    for(int i : v1)
    {
       cout<<i<<" ";
    }

    cout<<endl;
}  

#include <numeric>
#include <array>
#include <vector>
#include <iostream>
using namespace std;
 
int main()
{
vector<int> v(4) ;
//循环遍历赋值来初始化数组
//for(int i=1; i<=4; i++)
//{
//  v.push_back(i);
//}

//直接通过iota初始化数组，更简洁
  std::iota(v.begin(), v.end(), 1);
  for(auto n: v) {
    cout << n << ' ';
  }
  cout << endl;
  
  std::array<int, 4> array;
  std::iota(array.begin(), array.end(), 1);
  for(auto n: array) {
    cout << n << ' ';
  }
  std::cout << endl;
}

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

int main() {
  // your code goes here
  vector<int> v = { 1, 2, 5, 7, 9, 4 };
  auto result = minmax_element(v.begin(), v.end());
  
  cout<<*result.first<<" "<<*result.second<<endl;

  return 0;
}

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

int main() {
  vector<int> v = { 1, 2, 5, 7, 9, 4 };
  auto pos = is_sorted_until(v.begin(), v.end());
  
  for(auto it=v.begin(); it!=pos; ++it)
  {
    cout<<*it<< " ";
  }
  cout<<endl;
  
  bool is_sort = is_sorted(v.begin(), v.end());
  cout<< is_sort<<endl;
  return 0;
}