若一個算法是將常數時間O(1)問題的大小削減為其一部分,那麽該算法即爲O(log N),
37
Classic example:
while (x > 0) {
x/=2;
}
This will be:
Iteration | x
----------|--------
0 | x
1 | x/2
2 | x/4
... | ...
... | ...
k | x/2^k
2k = x → Applying log to both sides → k = log(x)