大约有 43,100 项符合查询结果（耗时：0.0282秒） [XML]
Truncate Two decimal places without rounding
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21 Answers
21
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Reorder levels of a factor without changing order of values
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121
Use the levels argument of factor:
df <- data.frame(f = 1:4, g = letters[1:4])
df
# f g
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Is there a list of screen resolutions for all Android based phones and tablets? [closed]
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130
(out of date) Spreadsheet of device metrics.
SEE ALSO:
Device Metrics - Material Design.
Scre...
Pythonic way to check if a list is sorted or not
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213
Actually we are not giving the answer anijhaw is looking for. Here is the one liner:
all(l[i] ...
What is Bit Masking?
...s an example of extracting a subset of the bits in the value:
Mask: 00001111b
Value: 01010101b
Applying the mask to the value means that we want to clear the first (higher) 4 bits, and keep the last (lower) 4 bits. Thus we have extracted the lower 4 bits. The result is:
Mask: 00001111b
Valu...
mongodb group values by multiple fields
...dr",
"book": "$book"
},
"bookCount": { "$sum": 1 }
}},
{ "$group": {
"_id": "$_id.addr",
"books": {
"$push": {
"book": "$_id.book",
"count": "$bookCount"
},
},
"count": { "$s...
How to determine the longest increasing subsequence using dynamic programming?
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19 Answers
19
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Replacing NAs with latest non-NA value
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18 Answers
18
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Generate all permutations of a list without adjacent equal elements
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12 Answers
12
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数据结构、算法复杂度一览表 - 更多技术 - 清泛网 - 专注IT技能提升
...O(|V|)
二分搜索
n元已排数组
O(log(n))
O(log(n))
O(1)
线性搜索(暴力法)
数组
O(n)
O(n)
O(1)
Dijkstra最短路径算法(最小堆作为优先队列)
图G(V,E), V为顶点集, E为边集
O((|V| + |E|) log |V|)
O((|V| + |E|) log |V|)
O(|V|...