unordered_set find() function in C++ STL
The unordered_set::find() function is a built-in function in C++ STL which is used to search for an element in the container. It returns an iterator to the element, if found else, it returns an iterator pointing to unordered_set::end().
Syntax :
unordered_set_name.find(key)
Parameter: This function accepts a mandatory parameter key which specifies the element to be searched for.
Return Value: It returns an iterator to the element if found, else returns an iterator pointing to the end of unordered_set.
Below programs illustrate the unordered_set::find() function:
Program 1:
CPP
// C++ program to illustrate the // unordered_set::find() function #include <iostream> #include <string> #include <unordered_set> using namespace std; int main() { unordered_set<string> sampleSet = { "Beginner1", "for", "Beginner2" }; // use of find() function if (sampleSet.find("Beginner1") != sampleSet.end()) { cout << "element found." << endl; } else { cout << "element not found" << endl; } return 0; } |
Output
element found.
Time Complexity: O(1)
Auxiliary Space: O(n)
Program 2:
CPP
// CPP program to illustrate the // unordered_set::find() function #include <iostream> #include <string> #include <unordered_set> using namespace std; int main() { unordered_set<string> sampleSet = { "Beginner1", "for", "Beginner2" }; // use of find() function if (sampleSet.find("w3wiki") != sampleSet.end()) { cout << "found" << endl; } else { cout << "Not found" << endl; } return 0; } |
Output
Not found
Time Complexity: O(1)
Auxiliary Space: O(n)
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