Searches for the last occurrence of the sequence[s_first, s_last) in the range[first, last).

[edit]Parameters

[edit]Return value

Iterator to the beginning of last occurrence of the sequence[s_first, s_last) in range[first, last).

If[s_first, s_last) is empty or if no such sequence is found,last is returned.

[edit]Complexity

Given\(\scriptsize N\)N asstd::distance(first, last) and\(\scriptsize S\)S asstd::distance(s_first, s_last):

[edit]Exceptions

The overloads with a template parameter namedExecutionPolicy report errors as follows:

• If execution of a function invoked as part of the algorithm throws an exception andExecutionPolicy is one of thestandard policies,std::terminate is called. For any otherExecutionPolicy, the behavior is implementation-defined.
• If the algorithm fails to allocate memory,std::bad_alloc is thrown.

[edit]Possible implementation

template<class ForwardIt1,class ForwardIt2>constexpr//< since C++20ForwardIt1 find_end(ForwardIt1 first, ForwardIt1 last,                    ForwardIt2 s_first, ForwardIt2 s_last){if(s_first== s_last)return last;     ForwardIt1 result= last;while(true){        ForwardIt1 new_result=std::search(first, last, s_first, s_last);if(new_result== last)break;else{            result= new_result;            first= result;++first;}}return result;}

template<class ForwardIt1,class ForwardIt2,class BinaryPred>constexpr//< since C++20ForwardIt1 find_end(ForwardIt1 first, ForwardIt1 last,                    ForwardIt2 s_first, ForwardIt2 s_last,                    BinaryPred p){if(s_first== s_last)return last;     ForwardIt1 result= last;while(true){        ForwardIt1 new_result=std::search(first, last, s_first, s_last, p);if(new_result== last)break;else{            result= new_result;            first= result;++first;}}return result;}

[edit]Example

#include <algorithm>#include <array>#include <cmath>#include <iostream> auto print_result=[](auto result,constauto& v){    result== v.end()?std::cout<<"Sequence not found\n":std::cout<<"Last occurrence is at: "<<std::distance(v.begin(), result)<<'\n';}; int main(){constauto v={1,2,3,4,1,2,3,4,1,2,3,4}; for(autoconst& x:{std::array{1,2,3},{4,5,6}}){auto iter= std::find_end(v.begin(), v.end(), x.begin(), x.end());// overload (1)        print_result(iter, v);} for(autoconst& x:{std::array{-1,-2,-3},{-4,-5,-6}}){auto iter= std::find_end(v.begin(), v.end(), x.begin(), x.end(),// overload (3)[](int x,int y){return std::abs(x)== std::abs(y);});        print_result(iter, v);}}

Last occurrence is at: 8Sequence not foundLast occurrence is at: 8Sequence not found

[edit]Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

[edit]See also

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