C++ boost::algorithm::one_of()














































C++ boost::algorithm::one_of()



Description:
The header 'boost/algorithm/cxx11/one_of.hpp'   contains the algorithm one_of() in C++ boost library. This function tests if one and only one of the element in the range returns 'true'  for some unary function. The unary function accepts each and every array elements individually and returns a Boolean value. The function also returns 'false' if the sequence is empty.

Syntax:
template <class InputIterator, class UnaryPredicate>
bool one_of(InputIterator first, InputIterator last, UnaryPredicate pred);


Parameters:
The following parameters are accepted by the function:
1.) first: It specifies the initial position of the sequence by input iterator (first is inclusive in range).
2.) last: It specifies the end position of the sequence by input iterator (last is exclusive in range).
3.) pred: It is a unary function that accepts the elements of the sequence in the range provided in argument. It returns a Boolean value where true indicates exactly one of the element in sequence have same property to that of the predicate.

The function returns true if one and only one element of the sequence returns true for the predicate else it returns false.


Program:
#include <iostream>
#include <vector>
#include <boost/algorithm/cxx11/one_of.hpp>

using namespace std;

int main()
{
    int n;
    cout << "Enter array size: ";
    cin >> n;
    cout << "Enter n elements: ";
    vector<int> A(n);
    for(int i = 0; i < n; i++)
        cin >> A[i];

    /* predicate which checks if exactly one
    *  element of the sequence is equal to 5.
    */
    auto predicate = [](char element) { return element == 5; };
    bool res1 = boost::algorithm::one_of(A.begin(), A.begin()+n, predicate); //for the range [0, n)
    //bool res2 = boost::algorithm::one_of(A, predicate); //for entire array

    if(res1)
        cout << "Exactly one element is equal to 5";
    else
        cout << "Exactly one element is not equal to 5";

    return 0;
}

Example:
1.) Enter array size: 5
     Enter n elements: 1 2 3 4 5
     Output: Exactly one element is equal to 5
2.) Enter array size: 5
     Enter n elements: 5 1 2 5 4
     Output: Exactly one element is not equal to 5


Complexity:
Time Complexity: The time complexity is linear between the first and last elements. Predicate is called for the same number of time.

Please write on comment section if you find any mistake or for any suggestions.

More Articles of Abhishek Kumar Singh:

Name Views Likes
C++ boost::range::replace_if 1020 0
C++ boost::range::copy_backward 759 1
C++ boost::range::max_element 1234 0
C++ boost::range::inplace_merge 686 0
C++ boost::range::copy 1351 1
C++ boost::algorithm::is_partitioned() 857 1
C++ boost::algorithm::copy_if() 1048 0
C++ boost::range::for_each (version 2) 768 0
C++ boost::range::set_symmetric_difference 684 0
C++ boost::remove_copy_if 769 0
C++ boost::range::set_intersection 1028 0
C++ boost::range::find_end 707 0
C++ boost::range::remove_erase_if 1652 0
C++ boost::range::push_back 1174 0
C++ boost::range::generate 672 0
C++ boost::algorithm::any_of() 739 0
C++ boost::range::insert 737 0
C++ boost::range::remove_erase 948 0
C++ boost::range::reverse 1266 0
C++ boost::algorithm::equal() 775 1
C++ boost::range::copy_n 848 0
C++ boost::range::random_shuffle 1286 1
C++ boost::algorithm::partition_point() 653 0
C++ boost::algorithm::one_of_equal() 545 0
C++ boost::algorithm::all_of() 918 1
C++ boost::range::merge 1059 0
C++ boost::range::reverse_copy 773 0
C++ boost::range::find 781 0
C++ boost::range::fill_n 627 0
Removing duplicate elements from std::vector (using std::unique and std::set) 2477 1
C++ boost::range::equal 739 0
C++ boost::algorithm::iota() 1015 0
C++ boost::range::is_sorted 852 0
test article 800 2
C++ boost::algorithm::is_permutation() 883 1
C++ boost::partial_sum 893 0
C++ boost::range::partial_sort 948 1
C++ boost::range::min_element 1085 0
C++ boost::range::iota 1084 0
C++ boost::range::set_union 736 0
C++ boost::algorithm::partition_copy() 1093 3
C++ boost::range::swap_ranges 634 0
C++ boost::range::for_each 920 0
C++ boost::range::upper_bound 1091 0
C++ boost::range::binary_search 1249 0
C++ boost::algorithm::all_of_equal() 569 0
C++ boost::algorithm::copy_n() 707 1
C++ boost::range::lower_bound 1048 0
C++ boost::algorithm::gather() 1534 0
C++ boost::algorithm::none_of_equal() 612 0
C++ boost::algorithm::one_of() 727 2
C++ boost::range::rotate 877 0
C++ boost::algorithm::any_of_equal() 881 0
Use of Comparator in C++ 2130 0
C++ boost::range::count 828 0
C++ boost::range::replace_copy_if 649 0
C++ boost::range::remove 841 2
C++ boost::remove_if 1463 1
C++ boost::range::nth_element 1155 1
C++ boost::range::partition 759 1
C++ boost::range::erase 672 0
C++ boost::range::fill 908 1
C++ boost::range::find_if 1364 0
C++ boost::range::lexicographical_compare 817 0
C++ boost::algorithm::none_of() 600 0
C++ boost::algorithm::hex() 3753 0
C++ boost::range::replace 751 0
C++ boost::range::replace_copy 825 1
C++ boost::range::set_difference 980 0
C++ boost::range::overwrite 729 0
C++ boost::range::count_if 982 0
C++ boost::range::push_front 674 0
C++ boost::range::includes 670 0
C++ boost::algorithm::is_sorted() 713 0
C++ boost::range::remove_copy 633 1
C++ boost::algorithm::minmax_element 632 1
Deletion of leaf node of a Binary Search Tree 1728 1
Nth Fibonacci Number (Recursive Solution, Dynamic Programming, Iterative Solution 3928 1
C++ boost::range::rotate_copy 664 0

Comments