s*****g
发帖数: 5159 | |
t****t
发帖数: 6806 | 2 i guess you were a java user
in c++ you don't have to initialize v by "v=vector();", or do anything
to release it.
you also don't have to write myClass a=myClass(); just write myClass a; is
enough.
【在 s*****g 的大作中提到】
: Say I have a class
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O*******d
发帖数: 20343 | |
t****t
发帖数: 6806 | 4 may i ask why is that?
【在 O*******d 的大作中提到】
: vector.push_back的效率很低。
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O*******d
发帖数: 20343 | |
t****t
发帖数: 6806 | 6 that has nothing to do with low efficiency of vector::push_back(), no?
【在 O*******d 的大作中提到】
: Vector or Deque? Vector的缺点需要Deque来弥补。
: http://faq.cprogramming.com/cgi-bin/smartfaq.cgi?answer=1069897449&id=1073086407
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O*******d
发帖数: 20343 | 7 Vector内部是一块连续的内存。 当capacity用完后，就要把全部数据转到新的更大的
连续内存上。
【在 t****t 的大作中提到】
: that has nothing to do with low efficiency of vector::push_back(), no?
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p***o
发帖数: 1252 | 8 1 You can reserve() if you know the final size.
2 Even w/o reserve, the amortized cost of push_back is still O(1).
【在 O*******d 的大作中提到】
: Vector内部是一块连续的内存。 当capacity用完后，就要把全部数据转到新的更大的
: 连续内存上。
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d****p
发帖数: 685 | 9 Among all STL containers, vector is the fastest if number of elements is
less than a modest number, say 100.
【在 O*******d 的大作中提到】
: vector.push_back的效率很低。
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