reversing

问题 This question already has answers here : Python reverse dictionary items order (3 answers) Closed 3 days ago . How do I reverse the order of key-value pairs of a dictionary, in Python? For example, I have this dictionary: {"a":1, "b":2, "c":3} I want to reverse it so that it returns: {"c":3, "b":2, "a":1} Is there a function that I haven't heard about that can do this? Some lines of code is fine as well. 回答1: Dictionary does not have any sense of order , so your key/value pairs are not

问题 I have a string in which every marked substring within < and > has to be reversed (the brackets don't nest). For example, "hello <wolfrevokcats>, how <t uoy era>oday?" should become "hello stackoverflow, how are you today?" My current idea is to loop over the string and find pairs of indices where < and > are. Then simply slice the string and put the slices together again with everything that was in between the markers reversed. Is this a correct approach? Is there an obvious/better solution?

问题 Here is the program I used: library(plotly) mydata = read.csv("data_to_plot.txt") df = as.data.frame(mydata) p <- df %>% group_by(X) %>% plot_ly(x = ~Y, y = ~X, z = ~Z, type = "scatter3d", mode = "lines") p and below is an excerpt of "mydata": df[1:12,] X Y Z 1 1 0.2818017 0.0005993884 2 1 0.2832173 0.0007896421 3 1 0.2846330 0.0010293849 4 1 0.2860487 0.0013282462 5 1 0.2874643 0.0016969544 I would like to have the X values reversed on the X-axis, but can't find how to modify my program.

问题 This question already has answers here : Closed 7 years ago . Possible Duplicate: Unable to reverse a linked list I'm trying to reverse a linked list: void LinkedList::reverseList() { Node *next=_head; Node *prev=0; while(next!=0) { Node *tmp=next->_next; next->_next=prev; prev=next; next=tmp; } } Lets say the list is: 4->3->2->1 When I print the list, I only see 1 (The print function is good). Any help? Thanks 回答1: Since you said you wanted to find the problem on your own, I'll just give you

问题 I'm making a function which reverses a string and checks if the string is a palindrome or not. When I test the function with a obvious palindrome like "abba", the function says it's not a palindrome. Also the forward string and the reversed string also differ in string length! #include <stdio.h> #include <string.h> char forward [] = "abba"; //The string to be reversed int size = (sizeof(forward)/sizeof(forward[0]) - 1); int j = 0; char reverse [10]; void reverser(char forward []) { printf("%s

问题 Why can't you just reverse the algorithm like you could reverse a math function? How is it possible to make an algorithm that isn't reversible? And if you use a rainbow table, what makes using a salt impossible to crack it? If you are making a rainbow table with brute force to generate it, then it invents each plaintext value possible (to a length), which would end up including the salt for each possible password and each possible salt (the salt and password/text would just come together as a

问题 I need to transmit some data over the wire and I don't want that data being plain text. The text I'm sending needs to be reversed so I can't md5/sha256/etc... What's a good way to encode a salted string? 回答1: You're looking for encryption . What language are you using? You probably have a built-in encryption algorithm you can use. The idea with hashing is that you can only go one-way. [plain text]--->(HASH ALGORITHM)--->HASH Whereas the idea with encryption is that you can use a key together

问题 So, I'm having some problems with dates that are reversing themselves in VBA when assigned to a Date variable. It's simpler than it sounds, but it's really bugging me. Code: Dim InsertedDate as Date On Error Resume Next InsertedDate = Me.BoxDate.Value If InsertedDate = 0 Then 'Do Something Else 'Do Something Different End If So let's assume that user types a value like 12/18/2017 I'm brazilian, so that means the user typed the 12th day of the 18th month. Since there's no 18th month in the

问题 I need some advice on how to reverse the contents of stdin. This is the part of my code which handles reversing stdin: int reversestdin(FILE *file) { int a, b; int lineas=0; while ((a=fgetc(stdin)) !=EOF) { if (a=='\n') lineas++; } for(b=0; b<lineas; b++) { rewind(stdin); int d,len, e; char str[2048], *ptr; for(e=0; e<=b; e++) { fgets(str, 2048, stdin); } ptr=str; for(d=0; d<2048; d++) { if(*ptr=='\n') break; if(*ptr=='\0') break; ptr++; } len=d; ptr--; for(d=len; d>0; d--) { printf("%c",

问题 I want to reshape my 24x20 matrices 'A' , 'B' , 'C' which are extracted from text file and are saved before and after normalizing by def normalize() in for-loop through cycles in such way that each cycles would be a row with all elements of 3 matrices side by side like below: [[A(1,1),B(1,1),C(1,1),A(1,2),B(1,2),C(1,2),...,A(24,20),B(24,20),C(24,20)] #cycle1 [A(1,1),B(1,1),C(1,1),A(1,2),B(1,2),C(1,2),...,A(24,20),B(24,20),C(24,20)] #cycle2 [A(1,1),B(1,1),C(1,1),A(1,2),B(1,2),C(1,2),...,A(24