std::search

std::search is a function in the C++ standard library that searches for a subsequence within a given sequence.

Syntax:

template<class ForwardIt1, class ForwardIt2>
ForwardIt1 search(ForwardIt1 first1, ForwardIt1 last1, ForwardIt2 first2, ForwardIt2 last2);

Parameters:
- first1, last1: Forward iterators to the initial and final positions of the sequence to search in.
- first2, last2: Forward iterators to the initial and final positions of the subsequence to search for.

Return value:
- Iterator to the first element of the first occurrence of the subsequence in the sequence. If the subsequence is not found, returns last1.

Example:

#include <iostream>
#include <algorithm>
#include <vector>

int main()
{
    std::vector<int> v {1, 2, 3, 4, 5, 6, 7, 8, 9};

    std::vector<int> sub {4, 5, 6};

    auto result = std::search(v.begin(), v.end(), sub.begin(), sub.end());

    if (result != v.end())
    {
        std::cout << "Subsequence found starting at index " << std::distance(v.begin(), result) << '\n';
    }
    else
    {
        std::cout << "Subsequence not found\n";
    }

    return 0;
}

Output:

Subsequence found starting at index 3