4.15日华为笔试

旧城等待， 2023-05-22 10:27 3阅读 0赞

# 参考： #

1.  [华为笔试，大家做的怎么样？][Link 1]
2.  [华为4.15笔试前两题AC - 正则表达式][4.15_AC -]
3.  [华为笔试2.7 4-15 - C++][2.7 4-15 - C]
4.  [华为4.15笔试 - C++][4.15_ - C]

# 题目简介： #

第一题：求获胜者，如果票数相当，按照字母排序，a>b>c,A>B>C,如果字母相同，则字母少的在前面，比如Luc>Lucy
    
    输入：
    Tom，Lily，Tom，Lucy，Lucy，Jack
    输出：
    Lucy

第二题：字符串匹配
    
    输入：
    read read[addr=0x17,mask=0xff,val=0x7],read_his[addr=0xff,mask=0xff,val=0x1],read[addr=0xf0,mask=0xff,val=0x80]
    输出：
    0x17 0xff 0x7
    0xf0 0xff 0x80

# 1. 第一题代码： #

## 1. 代码一：（通过率62.5%） ##

检验输入合法性就可以AC了，首字母大写，后边的字母小写。

import java.util.*;
    
    public class Main_1 { 
        public static void main(String[] args) { 
            Scanner sc  = new Scanner(System.in);
            if(sc.hasNextLine())
            { 
                String str = sc.nextLine();
                String s[] = str.split(",");
                Arrays.sort(s);
                if(s.length == 1)
                { 
                    System.out.println(s[0]);
                    return;
                }
                // for(int i = 0; i < s.length; i++)
                // { 
                // System.out.print(s[i] + " ");
                // }
                // System.out.println();
    
                int count = 1;
                int max = 0;
                int index = 0;
    
                for(int i = 0; i < s.length - 1; i++)
                { 
                    if((s[i]).equals(s[i + 1]))
                    { 
                        count++;                  
                    }
                    else
                    { 
                        count = 1;
                    }    
                    if(count > max)
                    { 
                        max = count;
                        index = i;
                    }
                }
                // System.out.println(max);
                // System.out.println(index);
                if(count == 1)
                { 
                    System.out.println(s[0]);
                    return;
                }
                else
                { 
                    System.out.println(s[index]);
                }
            }
            else
            { 
                System.out.println("error.0001");
                // System.exit(0);
            }        
        }
    }
    
    // 输入
    // 输出
    
    // Tom,Lily,Tom,Lucy,Lucy,Jack
    // Lucy
    
    // Tom,Lily,Tom,Lucy,Lucy,Tom,Jack
    // Tom
    
    // Tom,Lily,Tom,Lucy,Lucy,Jack,Tom,Tomy,Tomy,Tomy
    // Tom
    
    // Lily,Lily,Tom,Tom
    // Lily

## 2. 代码二：（AC） ##

import java.util.*;
    
    public class Main_1_2 { 
    
        public static void main(String[] args) { 
            Scanner sc = new Scanner(System.in);
            String str = sc.next();
            if (!str.matches("([A-Z][a-z]*,)*([A-Z][a-z]*)")) 
            { 
                System.out.println("error.0001");
            } 
            else 
            { 
                String[] strings = str.split(",");
                HashMap<String, Integer> map = new HashMap<String, Integer>();
                int max = 1;
                for (String s : strings) { 
                    map.put(s, map.getOrDefault(s, 0) + 1);
                    max = Math.max(max, map.get(s));
                }
                ArrayList<String> arrayList = new ArrayList<String>();
                for (String s : map.keySet()) { 
                    if (map.get(s) == max) { 
                        arrayList.add(s);
                    }
                }
                // System.out.println(arrayList.toString());
                arrayList.sort((s1, s2) -> s1.compareTo(s2));
                // System.out.println(arrayList.toString());
                System.out.println(arrayList.get(0));
            }
            sc.close();
        }
    }
    
    // 输入
    // 输出
    
    // Tom,Lily,Tom,Lucy,Lucy,Jack
    // Lucy
    
    // Tom,Lily,Tom,Lucy,Lucy,Tom,Jack
    // Tom
    
    // Tom,Lily,Tom,Lucy,Lucy,Jack,Tom,Tomy,Tomy,Tomy
    // Tom
    
    // Lily,Lily,Tom,Tom
    // Lily

## 3. 代码三：（AC） ##

#include <iostream>
    #include <vector>
    #include <unordered_map>
    #include <algorithm>
    using namespace std;
    
    bool cmp(pair<string, int> a, pair<string, int>b)
    { 
        if(a.second != b.second)
        { 
            return a.second > b.second;
        }
        else
        { 
            int len  = min(a.first.size(), b.first.size());
            for(int i = 0; i < len; i++)
            { 
                if(a.first[i] == b.first[i])
                { 
                    continue;
                }
                else
                { 
                    return a.first[i] < b.first[i];
                }
            }
            return a.first.size() < b.first.size();
        }
    }
    
    int main()
    { 
        string s;
        cin >> s;
        bool legal = true;
        string tmp = "";
        unordered_map<string, int> cnt;
        for(int i = 0;i < s.length(); i++)
        { 
            if(s[i] == ',')
            { 
                cnt[tmp]++;
                tmp.clear();
            }
            else if(s[i] >= 'a' && s[i] <= 'z')
            { 
                if(tmp.size() != 0)
                { 
                    tmp += s[i];
                }
                else
                { 
                    legal = false;
                    break;
                }
            }
            else if(s[i] >= 'A' && s[i] <= 'Z')
            { 
                if(tmp.size() == 0)
                { 
                    tmp += s[i];
                }
                else
                { 
                    legal = false;
                    break;
                }
            }
            else
            { 
                legal = false;
                break;
            }
        }
        if(legal == false)
        { 
            cout << "error.0001";
        }
        else
        { 
            cnt[tmp]++;
            vector< pair<string, int> > buf(cnt.begin(), cnt.end());
            sort(buf.begin(), buf.end(), cmp);
            cout << buf[0].first << endl;
        }
        return 0;
    }

# 2. 第二题代码： #

## 1. 代码一：（较全） ##

import java.util.*;
    
    // 输入1:
    // read read[addr=0x17,mask=0xff,val=0x7],read_his[addr=0xff,mask=0xff,val=0x1],read[addr=0xf0,mask=0xff,val=0x80]
    
    // 输出1:
    // 0x17 0xff 0x7
    // 0xf0 0xff 0x80
    
    // 输入2:
    // read read_his[addr=0xff,mask=0xff,val=0x1]
    
    // 输出2:
    // FAIL
    
    // 思路：
    // 先比对最前面那个字符串，然后是三个属性，顺序不能错，然后是数值，必须0x或者0X开头，然后还得有数，以上全通过才行。
    // 切分的时候容易弄混，多输出，弄一步输出一下就行。（需要注意检验数值是否十六进制）
    
    public class Main_2_1 { 
    
        public static boolean isHexNumber(String str)   // 判断字符串是否为十六进制数字
        { 
            boolean flag = true;
            for(int i = 0; i < str.length(); i++)
            { 
                char c = str.charAt(i);
                if((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'))
                { 
                    continue;                
                }
                else
                { 
                    flag = false;
                    break;
                }
            }
            return flag;
        }
    
        public static void main(String[] args) { 
            Scanner sc = new Scanner(System.in);
            while(sc.hasNextLine())
            { 
                String string = sc.nextLine();
                // System.out.println();
                string += ',';
                String a[] = string.split(" ");
                String key = a[0];
                String s = a[1];
                // System.out.println(key + " " + s);
                String str[] = s.split("],");
                // for(int i = 0; i < str.length; i++)
                // { 
                // System.out.println(str[i]);
                // }
                boolean flag = false;
                for(int i = 0; i < str.length; i++)
                { 
                    String sub[] = str[i].split("\\[");
                    // for(int j = 0; j < sub.length; j++)
                    // { 
                    // System.out.print(sub[j] + " ");
                    // }
                    // System.out.println();
                    for(int j = 0; j < sub.length - 1; j++)
                    { 
                        if((sub[j]).equals(key))
                        { 
                            // System.out.println(sub[j + 1]);
                            flag = true;
                            String res[] = sub[j + 1].split("addr=|,mask=|,val=");
                            // System.out.println(res.length);
                            boolean mark = true;
                            for(int k = 1; k < res.length; k++)
                            { 
                                if((res[k].startsWith("0x") && isHexNumber(res[k].substring(2))) || (res[k].startsWith("0X") && isHexNumber(res[k].substring(2))))
                                { 
                                    continue;
                                }
                                else
                                { 
                                    mark = false;
                                }
                            }
                            if(mark == true)
                            { 
                                for(int k = 1; k < res.length; k++)// k == 0时，res[0]输出的是空格：" "，所以要从k == 1开始输出
                                { 
                                    if(k != res.length - 1)
                                    { 
                                        System.out.print(res[k] + " ");
                                    }
                                    else
                                    { 
                                        System.out.println(res[k]);
                                    }
                                }
                            }
                            else if(mark == false)  // 三个地址中只要有一个不合法，就打印 FAIL
                            { 
                                System.out.println("FAIL");
                            }
                        }
                    }
                }
                if(flag == false)
                { 
                    System.out.println("FAIL");
                }
            }
            sc.close();
        }
    }
    
    // read read[addr=0x17,mask=0xff,val=0x7],read_his[addr=0xff,mask=0xff,val=0x1],read[addr=0xf0,mask=0xff,val=0x80]
    
    // read read_his[addr=0xff,mask=0xff,val=0x1]
    
    // read read[addr=0x17,mask=0xff,val=0z7]
    
    // read read[addr=0x17,mask=0xff,val=0xh]
    
    // read read[addr=0x17,mask=0xff,val=0xH]

## 2. 代码二：（AC） ##

import java.util.*;
    import java.util.regex.*;
    // import java.util.regex.Matcher;
    // import java.util.regex.Pattern;
    
    // 输入1:
    // read read[addr=0x17,mask=0xff,val=0x7],read_his[addr=0xff,mask=0xff,val=0x1],read[addr=0xf0,mask=0xff,val=0x80]
    
    // 输出1:
    // 0x17 0xff 0x7
    // 0xf0 0xff 0x80
    
    // 输入2:
    // read read_his[addr=0xff,mask=0xff,val=0x1]
    
    // 输出2:
    // FAIL
    
    // 思路：
    // 先比对最前面那个字符串，然后是三个属性，顺序不能错，然后是数值，必须0x或者0X开头，然后还得有数，以上全通过才行。
    // 切分的时候容易弄混，多输出，弄一步输出一下就行。（需要注意检验数值是否十六进制）
    
    public class Main_2_2 { 
        public static void main(String[] args) { 
            Scanner sc = new Scanner(System.in);
            while(sc.hasNext())
            { 
                String str = sc.next();
                Pattern pattern = Pattern.compile(str + "\\[addr=(0[xX][0-9a-fA-F]+),mask=(0[xX][0-9a-fA-F]+),val=(0[xX][0-9a-fA-F]+)\\]?");
                String[] strings = sc.next().split("],");
                boolean flag = false;
                for (String s : strings) { 
                    // System.out.println(s);
                    Matcher matcher = pattern.matcher(s);
                    if (matcher.matches()) { 
                        flag = true;
                        System.out.println(matcher.group(1) + " " + matcher.group(2) + " " + matcher.group(3));
                    }
                }
                if(flag == false)
                { 
                    System.out.println("FAIL");
                }    
            }
            sc.close();
        }
    }
    
    // read read[addr=0x17,mask=0xff,val=0x7],read_his[addr=0xff,mask=0xff,val=0x1],read[addr=0xf0,mask=0xff,val=0x80]
    
    // read read_his[addr=0xff,mask=0xff,val=0x1]
    
    // read read[addr=0x17,mask=0xff,val=0z7]
    
    // read read[addr=0x17,mask=0xff,val=0xh]
    
    // read read[addr=0x17,mask=0xff,val=0xH]

## 3. 代码三：（通过率67%） ##

再加上16进制的判断，应该就可以AC了。

// read read[addr=0x17,mask=0xff,val=0x7],read_his[addr=0xff,mask=0xff,val=0x1],read[addr=0xf0,mask=0xff,val=0x80]
    
    import java.util.*;
    
    public class Main { 
        public static void main(String[] args) { 
            Scanner sc = new Scanner(System.in);
            while(sc.hasNext())
            { 
                String in = sc.next();
                in = in + "[";
                String string[] = sc.next().split(",");
                // System.out.println(string.length);
                String inArr[] = new String[4];
                int count  = 0;
                for(int i = 0; i < string.length - 2; i = i + 3)
                { 
                    inArr[0] = string[i].split("addr=")[0];
                    inArr[1] = string[i].split("addr=")[1];
                    inArr[2] = string[i + 1].split("=")[1];
                    inArr[3] = string[i + 2].split("=")[1];
                    inArr[3] = inArr[3].split("\\]")[0];
    
                    // System.out.println("inArr[0]: " + inArr[0]);
                    // System.out.println("inArr[1]: " + inArr[1]);
                    // System.out.println("inArr[2]: " + inArr[2]);
                    // System.out.println("inArr[3]: " + inArr[3]);
    
                    if(in.equals(inArr[0]))
                    { 
                        System.out.print(inArr[1] + " " + inArr[2] + " " + inArr[3] + "\r\n");
                        count++;                    
                    }                
                    // System.out.println();
                }
                if(count == 0)
                { 
                    System.out.println("FAIL");
                }
            }
        }
    }

# 知识点： #

1.  计算机的十六进制数如何表示？  
    [十六进制数][Link 2]  
    [数的表示方法：十进制、二进制、八进制、十六进制等，以及二进制数的运算][Link 3]
2.  java中startsWith与endsWith的用法  
    [java中startsWith与endsWith的用法][java_startsWith_endsWith]  
    [Java startsWith() 方法][Java startsWith_]  
    [Java endsWith() 方法][Java endsWith_]
3.  Java substring() 方法  
    [Java substring() 方法][Java substring_]  
    [java关于substring(a)与substring(a,b)的用法][java_substring_a_substring_a_b]
4.  java 判断字符串是否为数字　十进制　十六进制  
    [java 判断字符串是否为数字　十进制　十六进制][java]
5.  java分割字符串 Unclosed character class near index 错误  
    [java分割字符串 Unclosed character class near index 错误][java_ Unclosed character class near index]  
    [Java中的坑之方括号][Java]  
    [Unclosed Character Class Error?][Unclosed Character Class Error]  
    [java.util.regex.PatternSyntaxException: Unclosed character class near index 0][java.util.regex.PatternSyntaxException_ Unclosed character class near index 0]
6.  Map.getOrDefault()方法  
    [Map.getOrDefault()方法][Map.getOrDefault]
7.  Map.keyset() 使用详解  
    [Map.keyset() 使用详解][Map.keyset_]  
    [Map集合中value（）方法与keySet（）、entrySet()区别][Map_value_keySet_entrySet]
8.  arrayList.sort((s1, s2) -> s1.compareTo(s2));的用法  
    [java中排序函数sort()使用，Arrays.sort（）和Collections.sort()][java_sort_Arrays.sort_Collections.sort]  
    [Java8 - 使用 Comparator.comparing 进行排序][Java8 - _ Comparator.comparing]
9.  java中判断两个字符串是否相等  
    [java中判断两个字符串是否相等的问题][java 1]  
    [Java compareTo() 方法][Java compareTo_]

# 吐槽两句： #

面向结果编程，学到了。。。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p5eF9seQ_size_16_color_FFFFFF_t_70]

[Link 1]: https://www.nowcoder.com/discuss/409142
[4.15_AC -]: https://www.nowcoder.com/discuss/409225
[2.7 4-15 - C]: https://www.nowcoder.com/discuss/409137
[4.15_ - C]: https://www.nowcoder.com/discuss/409150
[Link 2]: https://baike.baidu.com/item/%E5%8D%81%E5%85%AD%E8%BF%9B%E5%88%B6%E6%95%B0
[Link 3]: https://my.oschina.net/u/3185947/blog/3009709
[java_startsWith_endsWith]: https://blog.csdn.net/Evan123mg/article/details/46739501
[Java startsWith_]: https://www.runoob.com/java/java-string-startswith.html
[Java endsWith_]: https://www.runoob.com/java/java-string-endswith.html
[Java substring_]: https://www.runoob.com/java/java-string-substring.html
[java_substring_a_substring_a_b]: https://blog.csdn.net/qq_38039015/article/details/82222063
[java]: https://blog.csdn.net/wzhjava/article/details/9255497
[java_ Unclosed character class near index]: https://blog.csdn.net/idomyway/article/details/78816300
[Java]: https://my.oschina.net/u/3754001/blog/1932023
[Unclosed Character Class Error]: https://stackoverflow.com/questions/21816788/unclosed-character-class-error/21816839
[java.util.regex.PatternSyntaxException_ Unclosed character class near index 0]: https://stackoverflow.com/questions/24465134/java-util-regex-patternsyntaxexception-unclosed-character-class-near-index-0
[Map.getOrDefault]: https://blog.csdn.net/lxj_1993/article/details/79798963
[Map.keyset_]: https://www.cnblogs.com/ningvsban/archive/2013/05/06/3062208.html
[Map_value_keySet_entrySet]: https://blog.csdn.net/liu826710/article/details/9001254
[java_sort_Arrays.sort_Collections.sort]: https://www.cnblogs.com/zz22--/p/10705970.html
[Java8 - _ Comparator.comparing]: https://my.oschina.net/xinxingegeya/blog/2046405
[java 1]: https://www.cnblogs.com/zhmt/archive/2011/09/12/2174210.html
[Java compareTo_]: https://www.runoob.com/java/java-string-compareto.html
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p5eF9seQ_size_16_color_FFFFFF_t_70]: /images/20230521/953cdfda13204174a716d7bb0654b9b1.png