search_n
Prototype
template <class ForwardIterator, class Integer, class T>
ForwardIterator search_n(ForwardIterator first, ForwardIterator last,
Integer count, const T& value);
template <class ForwardIterator, class Integer,
class T, class BinaryPredicate>
ForwardIterator search_n(ForwardIterator first, ForwardIterator last,
Integer count, const T& value,
BinaryPredicate binary_pred);
Description
The first version of DefinitionDefined in the standard header algorithm, and in the nonstandard backward-compatibility header algo.h. Requirements on typesFor the first version:
For the first version:
Preconditions
ComplexityLinear. (The C++ standard permits the complexity to be O( Examplebool eq_nosign(int x, int y) { return abs(x) == abs(y); }
cout << "Searching for a sequence of "
<< count
<< " '" << val << "'"
<< (count != 1 ? "s: " : ": ");
int* result = search_n(first, last, count, val);
if (result == last)
cout << "Not found" << endl;
else
cout << "Index = " << result - first << endl;
}
void lookup_nosign(int* first, int* last, size_t count, int val) {
cout << "Searching for a (sign-insensitive) sequence of "
<< count
<< " '" << val << "'"
<< (count != 1 ? "s: " : ": ");
int* result = search_n(first, last, count, val, eq_nosign);
if (result == last)
cout << "Not found" << endl;
else
cout << "Index = " << result - first << endl;
}
int main() {
const int N = 10;
int A[N] = {1, 2, 1, 1, 3, -3, 1, 1, 1, 1};
lookup(A, A+N, 1, 4);
lookup(A, A+N, 0, 4);
lookup(A, A+N, 1, 1);
lookup(A, A+N, 2, 1);
lookup(A, A+N, 3, 1);
lookup(A, A+N, 4, 1);
lookup(A, A+N, 1, 3);
lookup(A, A+N, 2, 3);
lookup_nosign(A, A+N, 1, 3);
lookup_nosign(A, A+N, 2, 3);
}
The output is Searching for a sequence of 1 '4': Not found
Searching for a sequence of 0 '4's: Index = 0
Searching for a sequence of 1 '1': Index = 0
Searching for a sequence of 2 '1's: Index = 2
Searching for a sequence of 3 '1's: Index = 6
Searching for a sequence of 4 '1's: Index = 6
Searching for a sequence of 1 '3': Index = 4
Searching for a sequence of 2 '3's: Not found
Searching for a (sign-insensitive) sequence of 1 '3': Index = 4
Searching for a (sign-insensitive) sequence of 2 '3's: Index = 4
Notes[1] Note that [2] The reason that this range is See also |