C++ algorithm binary_search() function
Example
Find out if a value exists in a sorted vector:
vector<int> numbers = {1, 7, 3, 5, 9, 2};
sort(numbers.begin(), numbers.end());
if (binary_search(numbers.begin(), numbers.end(), 5)) {
cout << "The number 5 was found!";
} else {
cout << "The number 5 was not found.";
}Definition and Usage
The binary_search() function is an efficient algorithm to check if a value exists in a data range.
The data range must already be sorted. If the data range is not sorted then the function may return an incorrect result. The sort() function can be used to sort elements in the data range.
The range of data is specified by iterators.
Syntax
binary_search(iterator start, iterator end, <type> value);<type> refers to the type of the data that the range contains.
Parameter Values
| Parameter | Description |
|---|---|
| start | Required. An iterator pointing to the start of the data range being searched. |
| end | Required. An iterator pointing to the end of the data range being searched. Elements up to this position will be searched, but the element at this position will not be included. |
| value | Required. The value to search for. |
Technical Details
| Returns: | A boolean value:
|
|---|
Related Pages
Read more about data structures in our Data Structures Tutorial.
Read more about iterators in our Iterators Tutorial.
Read more about algorithms in our Algorithms Tutorial.
