阿里巴巴2021秋招笔试题20210806

Posted 2021-09-04 Starzkg

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$m$个月，一个月$d$天，一周$w$天
已知$m$，$d$，$w$
求第$k$年，第$j$月，第$i$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 [e-mail]
 * @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

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 [e-mail]
 * @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;
            }
        }
    }
}