unordered_multimap bucket_count() function in C++ STL Last Updated : 08 Aug, 2018 Summarize Comments Improve Suggest changes Share Like Article Like Report 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: CPP // 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: CPP // 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}, Comment More infoAdvertise with us Next Article unordered_multimap size() function in C++ STL G gopaldave Follow Improve Article Tags : Misc C++ STL CPP-Functions cpp-unordered_multimap +1 More Practice Tags : CPPMiscSTL Similar Reads Unordered Multimap in C++ STL In C++, the unordered_multimap is an unordered associative container that stores data in the form of key-value pairs. 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