duplicates

问题 this question might have similars in SO but my case is a bit different. and I tried to adapt those answers to my problem but couldn't. so here is the thing: I have this list : [(['c', 'a', 'b'], 10), (['c', 'a', 'b'], 9),(['h','b'],2)] for example. I want to remove the duplicates in this list by keeping tuple that has the larger number associated with it. so the list should look like this: [(['c', 'a', 'b'], 10),(['h','b'],2)] can anyone help me? the order of the items inside the inner lists

问题 I have an unlimited number of 12 byte messages arriving. The content can be treated as random and structureless. (The length is only important because it is shorter than most hashes.) I want to deduplicate them. One method is to store the last 1,000 messages in a circular buffer and check all 1,000 message for a match before accepting a message (and inserting it into the circular buffer for future checks). What other methods are there, which could be more CPU and memory efficient? 回答1: 12

问题 I have an array of hashes similar to this: [ {"student": "a","scores": [{"subject": "math","quantity": 10},{"subject": "english", "quantity": 5}]}, {"student": "b", "scores": [{"subject": "math","quantity": 1 }, {"subject": "english","quantity": 2 } ]}, {"student": "a", "scores": [ { "subject": "math", "quantity": 2},{"subject": "science", "quantity": 5 } ] } ] Is there a simpler way of getting the output similar to this except looping through the array and finding a duplicate and then

问题 I have a mapping table with a unique contraint on the tuple (c_id, t_id) . Here's some sample data to illustrate the situation: id c_id t_id ---------------- 1 10 2 2 10 3 3 10 7 4 12 2 5 13 3 I wrote a merge function for t_ids (x,y -> z OR x,y -> x). If my content ( c_id ) has both t_ids , then I'm of course violating the constraint by using this statement: UPDATE mapping_table SET t_id = '$target_tid' WHERE t_id = '$t1_id' OR t_id = '$t2_id'; The result would be: id c_id t_id --------------

问题 The table I am dealing with has multiple rows which have the same values for lat and lon . The example shows that 1 , 3 , 5 have the same location but the name attribute differs. The hash is built from name , lat and lon and differs therefore. BEFORE: id | name | lat | lon | flag | hash ----+------+-----+-----+------+------ 1 | aaa | 16 | 48 | 0 | 2cd <-- duplicate 2 | bbb | 10 | 22 | 0 | 3fc 3 | ccc | 16 | 48 | 0 | 8ba <-- duplicate 4 | ddd | 10 | 23 | 0 | c33 5 | eee | 16 | 48 | 0 | 751 <--

问题 I'm modifying phpBB's table to have bidirectional relationships for friends. Unfortuntately, people that have already added friends have created duplicate rows: user1 user2 friend 2 3 true 3 2 true 2 4 true So I'd like to remove rows 1 and 2 from the example above. Currently, this is my query built (doesn't work atm): DELETE FROM friends WHERE user1 IN (SELECT user1 FROM (SELECT f1.user1 FROM friends f1, friends f2 WHERE f1.user1=f2.user2 AND f1.user2=f2.user1 GROUP BY f1.user1) AS vtable);

问题 I have two frameworks in my Xcode project that both define a class with the same name (B.framework and C.framework both have a class named MyClass), resulting in a couple warnings like so: Duplicate symbol _OBJC_METACLASS_$_MyClass originally in B.framework/B(MyClass.o) now lazily loaded from C.framework/C(MyClass.o) Duplicate symbol _OBJC_CLASS_$_MyClass originally in B.framework/B(MyClass.o) now lazily loaded from C.framework/C(MyClass.o) Then at run time only one of the implementations is

问题 column A has: table pencil table table paper pencil paper so, all cells containing table should have yellow color, pencil should have blue, and paper should have red color, How to do this? 回答1: Give your input range the name "Argument" create another range "Template" where you list each element once and format it in the way you like (borders, styles, background colors etc. ...) run the following code Sub FormatFromList() Dim ArgCell As Range, TemplateCell As Range For Each ArgCell In Range(

问题 here's some sample data: date <- c("2012-01-01","2012-01-02","2012-01-02","2012-01-04","2012-01-05","2012-01-03","2012-01-05","2012-01-05","2012-01-01","2012-01-01") company <- c("A","A","A","A","A","B","B","B","C","C") var1 <- c(-0.01, -0.013, 0.02, 0.032, -0.002, 0.022, 0.012, 0.031, -0.018, -0.034) var2 <- c(43, 12, 34, 53, 45, 42, 23, 56, 87, 54) mydf1 <- data.frame(date, company, var1, var2) mydf1 # date company var1 var2 # 1 2012-01-01 A -0.010 43 # 2 2012-01-02 A -0.013 12 # 3 2012-01

问题 I've done some searching but I wasn't able to find a valid solution. I have an arraylist storing Strings such as gum, socks, OJ, dog food... I am having trouble iterating the list to determine the total number of differnt types of items. ie. ArrayList<String> Store = new ArrayList<String>(); this.Store.add("Gum"); this.Store.add("Gum"); this.Store.add("Socks"); this.Store.add("Candy"); The list has 4 total items, but only three different kinds of items (Gum, Sucks, Candy). How would I design