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Hashing a dictionary?
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@Ceaser That won't work because tuple implies ordering but dict items are unordered. frozenset is better.
– Antimony
Jul 30 '12 at 11:55
28
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How can building a heap be O(n) time complexity?
... useful; for example, when retrieving items with integer keys in ascending order or strings in alphabetical order. The principles are exactly the same; simply switch the sort order.
The heap property specifies that each node in a binary heap must be at least as large as both of its children. In part...
Finding row index containing maximum value using R
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See ?order. You just need the last index (or first, in decreasing order), so this should do the trick:
order(matrix[,2],decreasing=T)[1]
share
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map vs. hash_map in C++
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They are implemented in very different ways.
hash_map (unordered_map in TR1 and Boost; use those instead) use a hash table where the key is hashed to a slot in the table and the value is stored in a list tied to that key.
map is implemented as a balanced binary search tree (usuall...
Sort array of objects by single key with date value
...his ES6 one-liner might be of help. yourArr.sort((a, b) => a.yourNumericOrderingKey > b.yourNumericOrderingKey). In my case I had to sort based on an order key that was coming inside the objects of main array.
– keshavDulal
Sep 20 at 10:53
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#pragma pack effect
...B(3) | BB(4) |
| CC(1) | pad.. |
And sizeof(Test) would be 2 × 4 = 8.
Order of variables in struct is also important. With variables ordered like following:
struct Test
{
char AA;
char CC;
int BB;
};
and with #pragma pack(2), the struct would be laid out like this:
| 1 | 2 ...
Defining Z order of views of RelativeLayout in Android
I would like to define the z order of the views of a RelativeLayout in Android.
13 Answers
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Get the first key name of a javascript object [duplicate]
..." key in a hash (Javascript calls them objects). They are fundamentally unordered. Do you mean just choose any single key:
for (var k in ahash) {
break
}
// k is a key in ahash.
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imp...
MySQL INNER JOIN select only one row from second table
... = (
SELECT id
FROM payments AS p2
WHERE p2.user_id = u.id
ORDER BY date DESC
LIMIT 1
)
Or
SELECT u.*, p.*
FROM users AS u
INNER JOIN payments AS p ON p.user_id = u.id
WHERE NOT EXISTS (
SELECT 1
FROM payments AS p2
WHERE
p2.user_id = p.user_id AND
(p...
oracle top 替代方案 - 数据库(内核) - 清泛网 - 专注C/C++及内核技术
...案由于Oracle不支持select top 语句，所以在Oracle中经常是用order by 跟 rownum的组合来实现select top n的查询。select * from (...由于Oracle不支持select top 语句，所以在Oracle中经常是用order by 跟 rownum 的组合来实现select top n的查询。
select * f...