unordered_set bucket_size() in C++ STL
The unordered_set::bucket_size() function is a built-in function in C++ STL which returns the total number of elements present in a specific bucket in an unordered_set container.
The bucket is a slot in the unordered_set’s internal hash table where elements are stored.
Note: Buckets in unordered_set are numbered from 0 to n-1, where n is the total number of buckets.
Syntax:
unordered_set.bucket_size(n);
Parameter: This function accepts a single parameter n which is mandatory. This parameter represents the bucket number for which it is needed to find the total number of elements.
Return Value: This function returns the total number of elements present in the bucket n.
Below programs illustrate the unordered_set::bucket_size() function:
Program 1:
CPP
// CPP program to illustrate the// unordered_set::bucket_size() function#include <iostream>#include <unordered_set>using namespace std;int main(){ unordered_set<int> sampleSet; // to store number of buckets int bucketCount; // Inserting elements sampleSet.insert(5); sampleSet.insert(10); sampleSet.insert(15); sampleSet.insert(20); sampleSet.insert(25); bucketCount = sampleSet.bucket_count(); // displaying number of buckets cout << "sampleSet has " << bucketCount << " buckets\n"; // displaying number of elements in bucket numbered 1 cout << "Bucket number 3 contains " << sampleSet.bucket_size(3) << " elements"; return 0;} |
Output:
sampleSet has 7 buckets Bucket number 3 contains 1 elements
Program 2:
CPP
// CPP program to illustrate the// unordered_set::bucket_size() function#include <iostream>#include <unordered_set>using namespace std;int main(){ unordered_set<string> sampleSet; // to store number of buckets int bucketCount; // Inserting elements sampleSet.insert("Welcome"); sampleSet.insert("To"); sampleSet.insert("GeeksforGeeks"); sampleSet.insert("Computer Science Portal"); sampleSet.insert("For Geeks"); bucketCount = sampleSet.bucket_count(); // displaying number of buckets cout << "sampleSet has " << bucketCount << " buckets\n"; // displaying number of elements in bucket numbered 0 cout << "Bucket number 0 contains " << sampleSet.bucket_size(0) << " elements"; return 0;} |
Output:
sampleSet has 7 buckets Bucket number 0 contains 0 elements
