inverse

问题 I was wondering if anyone could tell me how to implement line 45 of the following pseudo-code. Require: the polynomial to invert a(x), N, and q. 1: k = 0 2: b = 1 3: c = 0 4: f = a 5: g = 0 {Steps 5-7 set g(x) = x^N - 1.} 6: g[0] = -1 7: g[N] = 1 8: loop 9: while f[0] = 0 do 10: for i = 1 to N do 11: f[i - 1] = f[i] {f(x) = f(x)/x} 12: c[N + 1 - i] = c[N - i] {c(x) = c(x) * x} 13: end for 14: f[N] = 0 15: c[0] = 0 16: k = k + 1 17: end while 18: if deg(f) = 0 then 19: goto Step 32 20: end if

问题 Bizzaro-Diff!!! Is there a away to do a bizzaro/inverse-diff that only displays the portions of a group of files that are the same? (I.E. way more than three files) Odd question, I know...but I'm converting someone's ancient static pages to something a little more manageable. 回答1: You want a clone detector. It detects similar code chunks across large source systems. See our ClonedR tool: http://www.semdesigns.com/Products/Clone/index.html 回答2: You could try the comm command (for common ). It

问题 Assume we have a domain class public class Incident { [Key] public virtual int IncidentId { get; set; } [Display(Name = "Parent Incident")] public virtual Incident ParentIncident { get; set; } [Display(Name = "Related Claim")] public virtual Incident ClaimIncident { get; set; } } Other properties are omitted for simplicity. When I had just ParentIncident in place, everything worked fine. Now I have added ClaimIncident to the class. I am attempting to update my database using the Entity

问题 Let's say I have an array A with n unique elements on the range [0, n) . In other words, I have a permutation of the integers [0, n). Is possible to transform A into B using O(1) extra space (AKA in-place) such that B[A[i]] = i ? For example: A B [3, 1, 0, 2, 4] -> [2, 1, 3, 0, 4] 回答1: Yes, it is possible, with O(n^2) time algorithm: Take element at index 0, then write 0 to the cell indexed by that element. Then use just overwritten element to get next index and write previous index there.

问题 It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 8 years ago . Hi i'm trying to figure out how to calculate the inverse of a quaternion. A code example would be awesome. Cheers 回答1: See Wikipedia article for the entire Quaternion math. Don't know what language you want to

问题 My Problem: I want to count inverse in the for loop. This is the opposite of what I want to do: for($i=1;$i<=10;$i++){ echo $i; } If I put $i-- doesn't works (my server crashes). Help meeee! Best Regards, Adam 回答1: When you say $i-- crashes your server, did you change the initialization and condition for $i ? for($i=10; $i>=1; $i--){ echo $i; } 回答2: If you take the for as you wrote and just replace $i++ with $i-- , the value of $i will be decremented with every iteration (1, 0, -1, -2, etc.)

问题 This is really a variation on this question, but not a duplicate: Python reverse / invert a mapping Given a dictionary like so: mydict= { 'a': ['b', 'c'], 'd': ['e', 'f'] } How can one invert this dict to get: inv_mydict = { 'b':'a', 'c':'a', 'e':'d', 'f':'d' } Note that values span uniquely under each key. Note : I previously had syntax map = ... and dict = ... Reminder not to use map and dict as they are built-in functions, see excellent comments and answers below :) 回答1: TL;DR Use

问题 This is really a variation on this question, but not a duplicate: Python reverse / invert a mapping Given a dictionary like so: mydict= { 'a': ['b', 'c'], 'd': ['e', 'f'] } How can one invert this dict to get: inv_mydict = { 'b':'a', 'c':'a', 'e':'d', 'f':'d' } Note that values span uniquely under each key. Note : I previously had syntax map = ... and dict = ... Reminder not to use map and dict as they are built-in functions, see excellent comments and answers below :) 回答1: TL;DR Use

问题 I didn't find any similar question to mine. I'm trying to write the gaussian-jordan inverse matrix algorithm. The idea of the algorithm is simple:) I want to inverse only a lower triangular matrix. I got almost correct answer. Where did I do sth wrong? Does anyone can help me? I will appreciate it. d _ A lower triangular matrix (nxn) dI identity matrix (nxn) n size of a matrix in one direction (n%16=0) dim3 threadsPerBlock(n/16,n/16); dim3 numBlocks(16,16); I know it is a simple

问题 For example, I call this function by passing a dictionary as parameter: >>> inv_map({'a':1, 'b':2, 'c':3, 'd':2}) {1: ['a'], 2: ['b', 'd'], 3: ['c']} >>> inv_map({'a':3, 'b':3, 'c':3}) {3: ['a', 'c', 'b']} >>> inv_map({'a':2, 'b':1, 'c':2, 'd':1}) {1: ['b', 'd'], 2: ['a', 'c']} If map = { 'a': 1, 'b':2 } I can only invert this map to get: inv_map = { 1: 'a', 2: 'b' } by using this dict((v,k) for k, v in map.iteritems()) Anyone knows how to do that for my case? 回答1: You can use a defaultdict