dynamic-arrays

问题 How is it possible to write Rust code like the C code below? This is my Rust code so far, without the option to marshal it: pub struct PackChar { id: u32, val_str: String, } #[no_mangle] pub extern "C" fn get_packs_char(size: u32) -> Vec<PackChar> { let mut out_vec = Vec::new(); for i in 0..size { let int_0 = '0' as u32; let last_char_val = int_0 + i % (126 - int_0); let last_char = char::from_u32(last_char_val).unwrap(); let buffer = format!("abcdefgHi{}", last_char); let pack_char =

问题 I am adding a formula to a worksheet via VBA which should be: =UNIQUE(IF(TableA[ColumnA]=A1,TableA[ColumnB],"")) This utilises the new SPILL feature in Excel to give me a list of column B values where the related value in column A matches what is in cell A. I'm also applying the UNIQUE function to remove any multiple blank ("") results. This works perfectly if I manually type the formula into Excel, however in using VBA to add the formula, Excel is adding @ symbols within the formula, and

问题 So I wrote a class that can parse XML documents and create SQL queries from it to update or insert new rows depending on the settings. Because the script has to work with any amount of nested blocks, the array that I'm putting all the values in has its path dynamically created much like the following example: $path = array('field1','field2'); $path = "['".implode("']['",$path)."']"; eval("\$array".$path."['value'] = 'test';"); Basically $path contains an array that shows how deep in the array

问题 I create a 2D array in C as follows: int **arr; arr = malloc(rows * sizeof(int *)); for (i = 0; i < rows; i++) arr[i] = malloc(cols * sizeof(int)); Now, I call: func(arr) In the function func , how do I calculate the row and column dimensions? 回答1: You can't calculate it - arr is just a pointer to a pointer, there is no more information associated with it (as with all C arrays). You have to pass the dimensions as separate arguments. 回答2: You can't. You have to pass the dimensions along with

问题 I create a 2D array in C as follows: int **arr; arr = malloc(rows * sizeof(int *)); for (i = 0; i < rows; i++) arr[i] = malloc(cols * sizeof(int)); Now, I call: func(arr) In the function func , how do I calculate the row and column dimensions? 回答1: You can't calculate it - arr is just a pointer to a pointer, there is no more information associated with it (as with all C arrays). You have to pass the dimensions as separate arguments. 回答2: You can't. You have to pass the dimensions along with

问题 I create a 2D array in C as follows: int **arr; arr = malloc(rows * sizeof(int *)); for (i = 0; i < rows; i++) arr[i] = malloc(cols * sizeof(int)); Now, I call: func(arr) In the function func , how do I calculate the row and column dimensions? 回答1: You can't calculate it - arr is just a pointer to a pointer, there is no more information associated with it (as with all C arrays). You have to pass the dimensions as separate arguments. 回答2: You can't. You have to pass the dimensions along with

问题 I've created an array of 2 objects, and I wish to write an 'add' function to dynamically add more people to this array. Can you explain why the 'add' function below does not add an object to the 'contacts' array successfully. var bob = { firstName: "Bob", lastName: "Jones", phoneNumber: "(650) 777-7777", email: "bob.jones@example.com" }; var mary = { firstName: "Mary", lastName: "Johnson", phoneNumber: "(650) 888-8888", email: "mary.johnson@example.com" }; var contacts = [bob, mary]; var

问题 I have a binary file where I store numbers as strings in this fashion: 11 43 89 101 etc I want, by using only system commands, to read the numbers stored and store them in a string dynamic array, because i don't know how long the strings will end up being or how many. Here is the relevant code: char **positions; int all_names=0,i,j; fd=open(argv[2],O_RDWR|O_CREAT,S_IRWXU); i=0; j=0; do{ positions=(char**)malloc(sizeof(char*)); (*positions)[i]=(char*)malloc((MAX_SIZE+1)*sizeof(char)); do{ read

问题 I have small function which creates html output according to my $schema array structure. Is it possible to have same output with my new array structure? (Is it possible to pass index names of arrays inside function) My original array structure. $schema = array( array( 'tag' => 'div', 'class' => 'lines', array( 'tag' => 'div', array( 'tag' => 'span', 'style' => 'margin:10px; padding:10px', 'key' => '$key-countryname', ), 'key' => '$value-country', ), array( 'tag' => 'div', array( 'tag' =>

问题 I am trying to get time in slot type. for example bike shop is open 9am to 9pm so we can get the bike in that time. if anyone books a bike in evening 5 pm to 7 pm slot then it should show 9am to 5pm (available), 5pm to 7pm (not available) and 7pm to 9pm (available) slots. so that another user who wants to book same bike they can understand the bike is not available for this slot and he can book on only available slots. me how to achieve this? 回答1: A model class to hold data class TimeSlot {