C++ STL 中 unordered_multimap bucket() 函数

unordered_multimap::bucket() 是 C++ STL 中的内置函数，其返回给定键所在的桶编号。桶的大小从0到bucket_count-1不等。

语法:

unordered_multimap_name.bucket(key)

参数: 函数接受一个必需的单一参数键，该键指定要返回其桶编号的键。

返回值: 它返回一个无符号整型，表示键所在的桶编号。

如下程序说明了上述功能：

程序1：

// C++ program to illustrate the
// unordered_multimap::bucket() 
#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 });
  
    // iterate for all elements and print its bucket number
    for (auto it = sample.begin(); 
                  it != sample.end(); it++) {
        cout << "The bucket number in which {" 
             << it->first << ", " 
             << it->second << "} is " 
             << sample.bucket(it->first) << endl;
    }
    return 0;
}

The bucket number in which {15, 150} is 1
The bucket number in which {30, 300} is 2
The bucket number in which {20, 200} is 6
The bucket number in which {10, 100} is 3
The bucket number in which {10, 100} is 3

程序2：

// C++ program to illustrate the
// unordered_multimap::bucket() 
#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' });
  
    // iterate for all elements and print its bucket number
    for (auto it = sample.begin(); 
                    it != sample.end(); it++) {
        cout << "The bucket number in which {" 
             << it->first << ", "
             << it->second << "} is " 
             << sample.bucket(it->first) << endl;
    }
    return 0;
}

The bucket number in which {c, b} is 1
The bucket number in which {r, a} is 2
The bucket number in which {b, c} is 0
The bucket number in which {a, b} is 6
The bucket number in which {a, b} is 6