303. region and retrieval - array immutable

Preface

C++ It's a high-level programming language , from C Language expansion and upgrading , As early as 1979 By Benjani · Strauss LUP is AT&T Developed by Bell studio .
C++ Both can be carried out C Process programming of language , It can also be used for object-based programming characterized by abstract data types , It can also carry out object-oriented programming characterized by inheritance and polymorphism .C++ Good at object-oriented programming at the same time , You can also do process based programming .
C++ Have the practical characteristics of computer operation , At the same time, it is also committed to improving the programming quality of large-scale programs and the problem description ability of programming languages .

Java Is an object-oriented programming language , Not only absorbed C++ The advantages of language , It's abandoned C++ The incomprehensible inheritance in 、 Concepts such as pointer , therefore Java Language has two characteristics: powerful and easy to use .Java As the representative of static object-oriented programming language , Excellent implementation of object-oriented theory , Allow programmers to do complex programming in an elegant way of thinking .
Java It's simple 、 object-oriented 、 Distributed 、 Robustness, 、 Security 、 Platform independence and portability 、 Multithreading 、 Dynamic and so on .Java Can write desktop applications 、Web Applications 、 Distributed system and embedded system applications, etc .

Python By Guido of the Dutch Society for mathematical and computer science research · Van rosum On 1990 It was designed in the early 's , As a course called ABC A substitute for language .Python Provides efficient advanced data structure , It's also a simple and effective way of object-oriented programming .Python Syntax and dynamic types , And the nature of interpretative language , Make it a programming language for scripting and rapid application development on most platforms , With the continuous update of the version and the addition of new language features , Gradually used for independent 、 Development of large projects .
Python The interpreter is easy to extend , have access to C Language or C++（ Or something else can be done through C Calling language ） Expand new functions and data types .Python It can also be used as an extensible programming language in customizable software .Python Rich library of standards , Provides source code or machine code for each major system platform .
2021 year 10 month , Compiler for language popularity index Tiobe take Python Crowned the most popular programming language ,20 Put it in... For the first time in years Java、C and JavaScript above .

describe

Given an array of integers   nums, Handle multiple queries of the following types :

    Calculation index left and right （ contain left and right） Between nums Elemental and , among left <= right

Realization NumArray class ：

    NumArray(int[] nums) Using arrays nums Initialize object
    int sumRange(int i, int j) Returns an array of nums Middle index left and right Between elements The sum of the , contain left and right At two o 'clock （ That is to say nums[left] + nums[left + 1] + ... + nums[right] )

Example 1：

Input ：
["NumArray", "sumRange", "sumRange", "sumRange"]
[[[-2, 0, 3, -5, 2, -1]], [0, 2], [2, 5], [0, 5]]
Output ：
[null, 1, -1, -3]

explain ：
NumArray numArray = new NumArray([-2, 0, 3, -5, 2, -1]);
numArray.sumRange(0, 2); // return 1 ((-2) + 0 + 3)
numArray.sumRange(2, 5); // return -1 (3 + (-5) + 2 + (-1))
numArray.sumRange(0, 5); // return -3 ((-2) + 0 + 3 + (-5) + 2 + (-1))

class NumArray {
    int[] sums;

    public NumArray(int[] nums) {
        int n = nums.length;
        sums = new int[n + 1];
        for (int i = 0; i < n; i++) {
            sums[i + 1] = sums[i] + nums[i];
        }
    }
    
    public int sumRange(int i, int j) {
        return sums[j + 1] - sums[i];
    }
}