阿里巴巴2021秋招笔试题20210806

╰半夏微凉° 2022-09-03 10:23 288阅读 0赞

源代码：https://gitee.com/shentuzhigang/mini-project/tree/master/exam-alibaba/exam-alibaba-20210806

# 第一题 #

## 题目描述 ##

大概定义了一年 m m m个月，一个月 d d d天，一周 w w w天  
已知 m m m， d d d， w w w  
求第 k k k年，第 j j j月，第 i i i天是星期几  
星期几用小写字母表示  
1<=w<=26  
其他数据范围忘了，反正很正常。

## 解决方案 ##

JAVA版本

package io.shentuzhigang.exam.alibaba;
    
    
    import java.util.Scanner;
    
    /** * @author ShenTuZhiGang * @version 1.0.0 * @email 1600337300@qq.com * @date 2021-08-06 19:16 */
    public class Exam2021080601 { 
        public static void main(String[] args) { 
            Scanner scanner = new Scanner(System.in);
            while (scanner.hasNext()) { 
                long d = scanner.nextLong();
                long m = scanner.nextLong();
                long w = scanner.nextLong();
    
                long i = scanner.nextLong();
                long j = scanner.nextLong();
                long k = scanner.nextLong();
                long result = ((k - 1) * m * d % w + (j - 1) * d % w + i % w) % w;
                System.out.println((char) (96 + (result == 0 ? w : result)));
            }
    
        }
    }

# 第二题 #

## 题目描述 ##

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzI3Mjc4MQ_size_16_color_FFFFFF_t_70][]  
有说明，没截到

## 样例输入 ##

> 7  
> 2 3 4 2  
> 1 3 4  
> 2 3 4 2  
> 2 3 4 5  
> 1 3 1  
> 2 6 4 5  
> 2 6 12 6

## 样例输出 ##

> NO  
> NO  
> YES  
> YES  
> YES

## 解决方案 ##

C++版本  
并查集

#include <stdio.h>
    #include <iostream>
    using namespace std;
    
    int t[20000];
    
    int find(int x) { 
        if (t[x] == 0) { 
            return x;
        }
        return find(t[x]);
    }
    
    void merge(int a, int b) { 
        int q =  find(a);
        int p = find(b);
        if (q != p ){ 
            t[q] = p;
        }
    }
    
    int main(){ 
        int n;
        scanf("%d",&n);
         for (int i = 0; i < n; i++) { 
             int op ,a,b,c;
             scanf("%d",&op);
             if (op == 1) { 
                 scanf("%d%d",&a,&b);
                 merge(a, b);
             } else if (op == 2) { 
                scanf("%d%d%d",&a,&b,&c);
                 int s = a % c;
                 int t = b % c;
                 printf( "%s\n",(find(s) == find(t) ? "YES" : "NO"));
             }
         }
    }

TLE的JAVA版本

package io.shentuzhigang.exam.alibaba;
    
    import java.util.Scanner;
    
    /** * @author ShenTuZhiGang * @version 1.0.0 * @email 1600337300@qq.com * @date 2021-008-06 19:46 */
    public class Exam2021080602 { 
    
        public static void main(String[] args) { 
            Scanner scanner = new Scanner(System.in);
            while (scanner.hasNext()) { 
                int n = scanner.nextInt();
                bcj z = new bcj();
                for (int i = 0; i < n; i++) { 
                    int op = scanner.nextInt();
                    if (op == 1) { 
                        int a = scanner.nextInt();
                        int b = scanner.nextInt();
                        z.merge(a, b);
                    } else if (op == 2) { 
                        int a = scanner.nextInt();
                        int b = scanner.nextInt();
                        int c = scanner.nextInt();
                        int s = a % c;
                        int t = b % c;
                        System.out.println(z.find(s) == z.find(t) ? "YES" : "NO");
                    }
                }
            }
        }
    
        static class bcj { 
            int[] t = new int[20000];
    
            public int find(int x) { 
                if (t[x] == 0) { 
                    return x;
                }
                return find(t[x]);
            }
    
            public void merge(int a, int b) { 
                int q = find(a);
                int p = find(b);
                if (q != p) { 
                    t[q] = p;
                }
            }
        }
    }

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