immutable c#

+1][col1]-accu[row1][col2+1] + accu[row1][col1] Java Code: Public classNummatrix {Private int[] accu; PublicNummatrix (int[] matrix) { if(Matrix = =NULL|| Matrix.length = = 0) { return; } intm =matrix.length; intn = matrix[0].length; Accu=New int[M+1] [N+1]; //base Case first Row/column are 0 default is 0 for(inti = 1; i){ for(intj = 1; J ) {Accu[i][j]= Accu[i-1][j] + accu[i][j-1]-accu[i-1][j-1] + matrix[i-1][j-1]; } } } Public i

Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by it upper left corner ( row1, Col1) and lower right corner ( row2, Col2). The above rectangle (with the red border) are defined by (row1, col1) = (2, 1) and (Row2, col2) = (4, 3), which contains Su m = 8.Example:Given matrix = [ [3, 0, 1, 4, 2], [5, 6, 3, 2, 1], [1, 2, 0, 1, 5], [4, 1, 0, 1, 7], [1, 0, 3, 0, 5]] Sumregion (2, 1, 4, 3), 8sumRegion (1, 1, 2, 2), 11sumRegion (1, 2, 2,

Topic:Given an integer array nums, find the sum of the elements between indices I and J (i ≤ J), inclusive.Example:Given nums = [-2, 0, 3, -5, 2, -1]sumrange (0, 2), 1sumRange (2, 5), -1sumrange (0, 5), 3Note: Assume that the array does is not a change. There is many calls to sumrange function. Your Numarray object would be instantiated and called as such:Numarray Numarray (nums);Numarray.sumrange (0, 1);Numarray.sumrange (1, 2);Ideas:The solution of all sumrange (0, I) is obta

1. Variable Objects immutable objects① for Python, the meaning of the variable = object means that the variable is bound to the object as a reference, and the object can be used with the variable name when the binding is complete. when an object does not have any object references, it enters the garbage collection process ( Automatic recycling mechanism). ② for a multi-element data structure, such as list,tuple,dict, its implementation is bound to th

Introduction to creation and use of OC-based immutable strings: Here are the basic usage of strings.1. Creation of strings//To create an OC constant stringNSString *str=@"Hello world!"; NSLog (@"%@", str); //Create an OC string with a C-language string Char*ch="Hello World C"; NSString*str2=[[NSString alloc] initwithutf8string:ch]; NSLog (@"%@", STR2); //u

The use of OC base mutable dictionaries with immutable dictionaries 1. Immutable dictionaries1.1 Creating an immutable dictionary //Create a dictionary//Note://1, the number of elements is even//2, each of the two elements is a key-value pair//3, value in front, key in rearNsdictionary *dic = [[Nsdictionary alloc] Initwithobjectsandkeys:@"Huang",@"name",@"

This is an old but still popular problem. The strings in Java are designed to be immutable for a number of reasons. The good answer depends on your memory, synchronization, data structure and so on better understanding, below, I summarize some answers. Requirements in the 1.String pool A string pool is a special type of storage area in the method region. When a string is created, if the string already exists in the pool, the reference to the existing

String is an immutable class in Java that cannot be modified once instantiated. Once an instance of an immutable class is created, the value of its member variable cannot be modified, and the immutable class has many advantages. Everyone knows why Java designers want to design it as an immutable class, and let's talk a

This content is I reprint from everywhere to collate, is my study notes, if involves the copyright question, please give me the message. Or the content of the wrong place, also please great God can help me to point out changes, thank you. One, the difference 1. String is a literal constant, while StringBuffer and StringBuilder are string variables. Character content created by string is immutable, and character content created by StringBuffer and Str

Disclaimer: this blog is an original blog and cannot be reproduced without permission! If you see it in other places, it is recommended to take a look at csdn (the original link for the http://blog.csdn.net/bettarwang/article/details/26744661), read the code and ask questions, discussion is more convenient. In Java, final is mainly used in three aspects: Variable modification, modification method and modification class. The role of final is explained in the following two aspects. At the end of t

Python Basics-Basic data type (number (numeric) string (string) list (list) Tuple (tuple) sets (collection) Dictionary (dictionary))There are six standard data types in the Python3:Number (numeric)String (String)List (lists)Tuple (tuple)Sets (collection)Dictionary (dictionary)Among the six standard data types of Python3:Immutable data (four): Number, String (string), tuple (tuple), sets (set);Variable data (two): List, Dictionary (dictionary).Python3

%@", Idx,obj); } }]; Variable group NsmutablearrayVariable group Nsmutablearray inherit from immutable group Nsarray //1. Create an empty array Nsmutablearray *array =[nsmutablearray array]; //2. Dimension array append element [array addobject:@1 ]; //3. Creating an array, adding multiple elements nsmutablearray *array2 = [Nsmutablearray arraywithcapacity:5"; //add 5 Elements [array2 addobject:@1]; array2[ 1] = @2; Array2[2] = @3; Array2[3] = @4; A

Immutable objects has many advantages, including: Safe for use by untrusted libraries. Thread-safe:can is used by many threads with no risk of race conditions. doesn ' t need to support mutation, and can make time and space savings with that assumption. All immutable collection implementations is more memory-efficient than their mutable siblings (analysis) Can is used as a constant, wit

Background:Find out if Python's data types are mutable, or better understand Python's use of memory.Variable and immutable definitionsVariable data type: Defines a variable in python that, when the value of the variable is modified, the memory address is not changed (the object is unchanged), the data is defined as a mutable data type.Immutable data type: When a variable's value is modified, the memory address of the variable is changed (a new object

Let's take a look at one of the following examples: Copy Code code as follows: Import Java.math.BigInteger; public class Bigproblem { public static void Main (string[] args) { BigInteger Fivethousand = new BigInteger ("5000"); BigInteger Fiftythousand = new BigInteger ("50000"); BigInteger Fivehundredthousand = new BigInteger ("500000"); BigInteger total = Biginteger.zero; Total.add (Fivethousand); Total.add (Fiftythousand); Total.add (Fivehundredthousand); SYSTEM.OUT.PRINT

When the state of an object is immutable, it is considered an immutable object, and the use of immutable objects as much as possible is recognized as an effective way to build simple and reliable code. Immutable objects are useful in concurrent programs and cannot be corrupted by thread interference or considered incon

This article is divided into the following sections Concept Address issues As a function parameter Variable parameters are used in a class function default Parameters Differences in the implementation of the class ConceptThe difference between a mutable object and an immutable object is whether the object itself is mutable.Some of the types built into Python mutable objects: List dict set

Tag: Address design operation cannot data access style serial RACHere, the immutable string is no longer discussed, just to say why the string is immutable.Rough point, straight to the, string of the immutable reason there are three:1). The String class is finalA class with a final decoration cannot be inherited, and it is used in the string class to represent that it cannot be inherited, and it cannot be i

Why is the Python function definition default parameter must point to the immutable object?The following is a personal understanding, if there is a wrong place, welcome to discussCause analysis: When defined, the function allocates the memory space of the object to which the function and default parameter L point.1. If L is pointing to a mutable object, and the variable object is updated in the function, the variable object is created when the functio

string is immutable, no matter what happens, the content of an already created string is not changed, and any similar modifications to it are actually new to a string object.So, why do you define immutable objects? Cache Hashcode The hash code (hashcode) of a string is often used in Java. For example, in HashMap, the immutable character of a string