Acwing 第 95 场周赛

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Acwing 第 95 场周赛

• A AcWing 4873. 简单计算

  • 题意

    给定四个整数 x1,y1,x2,y2，请你计算 max(|x1−x2|,|y1−y2|)

  • 思路

    模拟

  • 代码

    '''
    Author: NEFU AB-IN
    Date: 2023-03-31 21:50:42
    FilePath: \Acwing\95cp\a\a.py
    LastEditTime: 2023-03-31 21:51:38
    '''
    # import
    import sys, math
    from collections import Counter, deque
    from heapq import heappop, heappush
    from bisect import bisect_left, bisect_right
    
    # Final
    N = int(1e3 + 10)
    INF = int(2e9)
    
    # Define
    sys.setrecursionlimit(INF)
    read = lambda: map(int, input().split())
    
    # —————————————————————Division line ————————————————————————————————————————
    
    x1, y1 = read()
    x2, y2 = read()
    
    print(max(abs(x1 - x2), abs(y1 - y2)))
    

• B AcWing 4874. 约数

  • 题意

    如果一个正整数的约数个数恰好为 ，则称该数为美丽数。
    给定 n个正整数 a1,a2,…,an，请你依次判断每个数是否是美丽数。

  • 思路

    由算数基本定理就可以退出约数个数的式子
    $cnt=(p_1+1)\ast (p_2+1)\ast ...$
    如果只有三个约数，除去1和其本身$n$，也就是只有一个质因数因子，也就是$cnt=p_1+1=3$，$p_1=2$，$n=p_1^2$，也就是说，n是某个质数的完全平方数
    所以，先判断n是不是完全平方数，再判断sqrt(n)是不是质数即可

  • 代码

    # import
    import sys, math
    from collections import Counter, deque
    from heapq import heappop, heappush
    from bisect import bisect_left, bisect_right
    
    # Final
    N = int(1e6 + 10)
    INF = int(2e9)
    
    # Define
    sys.setrecursionlimit(INF)
    read = lambda: map(int, input().split())
    
    # —————————————————————Division line ————————————————————————————————————————
    st, prime = [0] * N, []
    
    
    def init():
        st[0] = st[1] = 1
        for i in range(2, N):
            if st[i] == 0:
                prime.append(i)
            for j in range(len(prime)):
                if i * prime[j] >= N:
                    break
                st[i * prime[j]] = 1
                if i % prime[j] == 0:
                    break
    
    
    init()
    n, = read()
    a = list(read())
    
    for x in a:
        y = int(math.sqrt(x))
        if y * y == x:
            if st[y] == 0:
                print("YES")
            else:
                print("NO")
        else:
            print("NO")
    
    

• C AcWing 4875. 整数游戏

  • 题意

    略

  • 思路

    link
    直接放网址了，讲的有道理

  • 代码

    '''
    Author: NEFU AB-IN
    Date: 2023-03-31 21:50:42
    FilePath: \Acwing\95cp\c\c.py
    LastEditTime: 2023-04-01 00:48:47
    '''
    # import
    import sys, math
    from collections import Counter, deque
    from heapq import heappop, heappush
    from bisect import bisect_left, bisect_right
    
    # Final
    N = int(1e3 + 10)
    INF = int(2e9)
    
    # Define
    sys.setrecursionlimit(INF)
    read = lambda: map(int, input().split())
    
    # —————————————————————Division line ————————————————————————————————————————
    
    
    def solve():
        n, = read()
        a = list(read())
        x = min(a)
        print("Alice" if x != a[0] else "Bob")
    
    
    for _ in range(int(input())):
        solve()