318. maximum word length product

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

Here's an array of strings words , Find out and return to length(words[i]) * length(words[j]) The maximum of , And these two words don't have a common letter . If there are no such two words , return 0 .

Example 1：

Input ：words = ["abcw","baz","foo","bar","xtfn","abcdef"]
Output ：16
explain ： These two words are "abcw", "xtfn".

Example 2：

Input ：words = ["a","ab","abc","d","cd","bcd","abcd"]
Output ：4
explain ： These two words are "ab", "cd".

Example 3：

Input ：words = ["a","aa","aaa","aaaa"]
Output ：0
explain ： There are no such two words .

class Solution {
    public int maxProduct(String[] words) {
        int length = words.length;
        int[] masks = new int[length];
        for (int i = 0; i < length; i++) {
            String word = words[i];
            int wordLength = word.length();
            for (int j = 0; j < wordLength; j++) {
                masks[i] |= 1 << (word.charAt(j) - 'a');
            }
        }
        int maxProd = 0;
        for (int i = 0; i < length; i++) {
            for (int j = i + 1; j < length; j++) {
                if ((masks[i] & masks[j]) == 0) {
                    maxProd = Math.max(maxProd, words[i].length() * words[j].length());
                }
            }
        }
        return maxProd;
    }
}