The unordered_multimap::bucket_count() is a built-in function in C++ STL which returns the total number of buckets in the unordered_multimap container. A bucket is a slot in the container’s internal hash table to which elements are assigned based on their hash value.
Syntax:
unordered_multimap_name.bucket_count()
Parameters: The function does not accept any parameter.
Return Value: It returns an unsigned integral type which denotes the total count of buckets.
Below programs illustrate the above function:
Program 1:
// C++ program to illustrate the // unordered_multimap::bucket_count() #include <bits/stdc++.h> using namespace std;
int main()
{ // declaration
unordered_multimap< int , int > sample;
// inserts key and element
sample.insert({ 10, 100 });
sample.insert({ 10, 100 });
sample.insert({ 20, 200 });
sample.insert({ 30, 300 });
sample.insert({ 15, 150 });
cout << "The total count of buckets: " << sample.bucket_count();
// prints all element bucket wise
for ( int i = 0; i < sample.bucket_count(); i++) {
cout << "\nBucket " << i << ": " ;
// if bucket is empty
if (sample.bucket_size(i) == 0)
cout << "empty" ;
for ( auto it = sample.cbegin(i);
it != sample.cend(i); it++)
cout << "{" << it->first << ", " << it->second << "}, " ;
}
return 0;
} |
Output:
The total count of buckets: 7 Bucket 0: empty Bucket 1: {15, 150}, Bucket 2: {30, 300}, Bucket 3: {10, 100}, {10, 100}, Bucket 4: empty Bucket 5: empty Bucket 6: {20, 200},
Program 2:
// C++ program to illustrate the // unordered_multimap::bucket_count() #include <bits/stdc++.h> using namespace std;
int main()
{ // declaration
unordered_multimap< char , char > sample;
// inserts key and element
sample.insert({ 'a' , 'b' });
sample.insert({ 'a' , 'b' });
sample.insert({ 'b' , 'c' });
sample.insert({ 'r' , 'a' });
sample.insert({ 'c' , 'b' });
cout << "The total count of buckets: " << sample.bucket_count();
// prints all element bucket wise
for ( int i = 0; i < sample.bucket_count(); i++) {
cout << "\nBucket " << i << ": " ;
// if bucket is empty
if (sample.bucket_size(i) == 0)
cout << "empty" ;
for ( auto it = sample.cbegin(i);
it != sample.cend(i); it++)
cout << "{" << it->first << ", " << it->second << "}, " ;
}
return 0;
} |
Output:
The total count of buckets: 7 Bucket 0: {b, c}, Bucket 1: {c, b}, Bucket 2: {r, a}, Bucket 3: empty Bucket 4: empty Bucket 5: empty Bucket 6: {a, b}, {a, b},