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std::cin input with spaces?
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answered Apr 30 '11 at 0:52
PetePete
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Removing a model in rails (reverse of “rails g model Title…”)
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edited Jul 22 '13 at 19:43
answered Aug 18 '11 at 10:35
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Should you always favor xrange() over range()?
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12 Answers
12
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Understanding spring @Configuration class
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152
Migrating XML to @Configuration
It is possible to migrate the xml to a @Configuration in a few ...
Repeat each row of data.frame the number of times specified in a column
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Here's one solution:
df.expanded <- df[rep(row.names(df), df$freq), 1:2]
Result:
var1 var2
1 a d
2 b e
2.1 b e
3 c f
3.1 c f
3.2 c f
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im...
Difference between JVM and HotSpot?
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edited Aug 2 '18 at 11:54
answered May 15 '13 at 15:05
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What exception classes are in the standard C++ library
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2 Answers
2
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Find a pair of elements from an array whose sum equals a given number
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edited Sep 12 at 14:53
hjpotter92
68.2k2525 gold badges117117 silver badges154154 bronze badges
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How to test if list element exists?
...to check that the name is actually defined in the list:
foo <- list(a=42, b=NULL)
foo
is.null(foo[["a"]]) # FALSE
is.null(foo[["b"]]) # TRUE, but the element "exists"...
is.null(foo[["c"]]) # TRUE
"a" %in% names(foo) # TRUE
"b" %in% names(foo) # TRUE
"c" %in% names(foo) # FALSE
...and foo[["...