It is more efficient to calculate this iterator directly than to write an equivalent program that increments the iterator one by one until it reaches the middle element.

这种直接计算迭代器的方法，与用迭代器逐个元素自增操作到达中间元素的方法是等价的，但前者的效率要高得多。

youdao

It is more efficient to calculate this iterator directly than to write an equivalent program that increments the iterator one by one until it reaches the middle element.

这种直接计算迭代器的方法，与用迭代器逐个元素自增操作到达中间元素的方法是等价的，但前者的效率要高得多。

youdao