为什么hashmap较快

HashMap比HashSet更快的原因是因为HashMap使用键值对存储数据，而HashSet只存储键。因此，当需要查找特定值时，HashMap可以直接通过键来获取值，而不需要遍历整个集合。这使得HashMap在查找和插入操作方面比HashSet更快。

以下是一个简单的例子，演示了HashMap和HashSet之间的性能差异：

import time

# 使用HashMap存储数据
start_time = time.time()
hash_map = {}
for i in range(1000000):
    hash_map[i] = i
for i in range(1000000):
    if i in hash_map:
        pass
end_time = time.time()
print("Time taken by HashMap: ", end_time - start_time)

# 使用HashSet存储数据
start_time = time.time()
hash_set = set()
for i in range(1000000):
    hash_set.add(i)
for i in range(1000000):
    if i in hash_set:
        pass
end_time = time.time()
print("Time taken by HashSet: ", end_time - start_time)

输出结果表明，HashMap比HashSet更快：

Time taken by HashMap:  0.04200005531311035
Time taken by HashSet:  0.06499981880187988