第十四届蓝桥杯大赛软件组省赛 Python大学A组 个人暴力题解

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文章目录

  • Python大学A组 个人暴力题解
    • 试题 A: 特殊日期
      • 题意
      • 思路
      • 代码
    • 试题 B: 分糖果
      • 题意
      • 思路
      • 代码
    • 试题 C: 三国游戏
      • 题意
      • 思路
      • 代码
    • 试题 D: 平均
      • 题意
      • 思路
      • 代码
    • 试题 E: 翻转
      • 题意
      • 思路
      • 代码
    • 试题 F: 子矩阵
      • 题意
      • 思路
      • 代码
    • 试题 G: 阶乘的和
      • 题意
      • 思路
      • 代码
    • 试题 H: 奇怪的数
      • 题意
      • 思路
      • 代码
    • 试题 I: 子树的大小
      • 题意
      • 思路
      • 代码
    • 试题 J: 反异或 01 串
      • 题意
      • 思路
      • 代码

博主个人的暴力题解,基本很少是正解,求轻喷

Python大学A组 个人暴力题解

  • 试题 A: 特殊日期

    • 题意

    • 思路

      模拟即可,本身想用Python自带的datetime库,结果发现年不能开那么大,就直接手写了

    • 代码

      '''
      Author: NEFU AB-IN
      Date: 2023-04-08 14:15:52
      FilePath: \Vscode\ACM\LanQiao\2023PythonA\a.py
      LastEditTime: 2023-04-08 14:19:47
      '''
      # AB-IN AK Lanqiao !!
      # http://222.27.161.91/home.page
      # aR7H4tDF
      import sys, math
      from collections import Counter, deque, defaultdict
      from bisect import bisect_left, bisect_right
      from heapq import heappop, heappush, heapify
      from typing import *
      from datetime import datetime, timedelta
      
      N = int(1e6 + 10)
      INF = int(2e9)
      
      sys.setrecursionlimit(INF)
      read = lambda: map(int, input().split())
      
      
      class sa:
          def __init__(self, y, m, d):
              self.y = y
              self.m = m
              self.d = d
      
          def __lt__(self, x):
              pass
      
      
      # ---------------divrsion line ----------------
      
      # t1 = datetime(2000, 1, 1)
      # t2 = datetime(2000, 1, 2)
      
      # ans = 0
      # while True:
      #     if t1.year % t1.month == 0 and t1.year % t1.day == 0:
      #         ans += 1
      #     t1 = t1 + timedelta(days=1)
      #     if t1 == t2:
      #         break
      # print(ans)
      
      mouths = [0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
      
      
      def func(t1):
          y, m, d = t1.y, t1.m, t1.d
          if (y % 4 == 0 and y % 100) or (y % 400 == 0):
              mouths[2] = 29
          else:
          	mouths[2] = 28
          d += 1
          if d > mouths[m]:
              d = 1
              m += 1
          if m > 12:
              m = 1
              y += 1
          return sa(y, m, d)
      
      
      t1 = sa(2000, 1, 1)
      t2 = sa(2000000, 1, 2)
      
      ans = 0
      while True:
          if t1.y % t1.m == 0 and t1.y % t1.d == 0:
              ans += 1
          t1 = func(t1)
          if t1.y == t2.y and t1.m == t2.m and t1.d == t2.d:
              break
      print(ans)
      
      # 35813063
      
  • 试题 B: 分糖果

    • 题意

    • 思路

      DFS爆搜即可

    • 代码

      # AB-IN AK Lanqiao !!
      import sys, math
      from collections import Counter, deque, defaultdict
      from bisect import bisect_left, bisect_right
      from heapq import heappop, heappush, heapify
      from typing import *
      from datetime import datetime, timedelta
      
      N = int(1e6 + 10)
      INF = int(2e9)
      
      sys.setrecursionlimit(INF)
      read = lambda : map(int, input().split())
      
      class sa:
          def __init__(self, x, y):
              self.x = x
              self.y = y
          def __lt__(self, x):
              pass
      
      # ---------------divrsion line ----------------
      # 两种糖果分别有 9 个和 16 个,要全部分给 7 个小朋友,每个小朋友得到
      # 的糖果总数最少为 2 个最多为 5 个,问有多少种不同的分法。
      
      ans = 0
      def dfs(sum1, sum2, cnt):
          global ans
          if sum1 < 0 or sum2 < 0:
              return
          if cnt == 8:
              if sum1 == 0 and sum2 == 0:
                  ans += 1
              return
          for i in range(2, 6):
              dfs(sum1 - i, sum2, cnt + 1)
          for i in range(2, 6):
              dfs(sum1, sum2 - i, cnt + 1)
          for i in range(2, 6):
              for j in range(2, 6):
                  if i + j >= 2 and i + j <= 5:
                      dfs(sum1 - i, sum2 - j, cnt + 1)
      
      dfs(9, 16, 1)
      print(ans)
      
      # 148540
      
  • 试题 C: 三国游戏

    • 题意

    • 思路

      直接没思路,一看到数据范围瞬间怂了,脑子里想的只有暴力,这个题是留到最后写的,就写了个最差的二进制枚举

    • 代码

      # AB-IN AK Lanqiao !!
      import sys, math
      from collections import Counter, deque, defaultdict
      from bisect import bisect_left, bisect_right
      from heapq import heappop, heappush, heapify
      from typing import *
      from datetime import datetime, timedelta
      
      N = int(1e6 + 10)
      INF = int(2e9)
      
      sys.setrecursionlimit(INF)
      read = lambda : map(int, input().split())
      
      class sa:
          def __init__(self, x, y):
              self.x = x
              self.y = y
          def __lt__(self, x):
              pass
      
      # ---------------divrsion line ----------------
      # 最差方法 二进制枚举
      
      n, = read()
      a = list(read())
      b = list(read())
      c = list(read())
      ans = 0
      
      for i in range(1 << n):
          A, B, C, cnt = 0, 0, 0, 0
          for j in range(n):
              if i & 1 << j:
                  A += a[j]
                  B += b[j]
                  C += c[j]
                  cnt += 1
          if A > B + C or B > A + C or C > A + B:
              ans = max(ans, cnt)
      
      print(ans if ans != 0 else -1)
      
  • 试题 D: 平均

    • 题意

    • 思路

      唯一一个觉得暴力是正解的题
      就是每个数最多就是n//10个,所以就去掉多的数,然后是那些数中代价小的,最后采用了前缀和优化了一下

    • 代码

      # AB-IN AK Lanqiao !!
      import sys, math
      from collections import Counter, deque, defaultdict
      from bisect import bisect_left, bisect_right
      from heapq import heappop, heappush, heapify
      from typing import *
      from datetime import datetime, timedelta
      
      N = int(1e6 + 10)
      INF = int(2e9)
      
      sys.setrecursionlimit(INF)
      read = lambda : map(int, input().split())
      
      class sa:
         def __init__(self, a, b):
             self.a = a
             self.b = b
         def __lt__(self, t):
             if self.a != t.a:
                 return self.a < t.a
             return self.b < t.b
      
      # ---------------divrsion line ----------------
      
      n, = read()
      lst = [[] for _ in range(10)]
      
      for i in range(n):
         a, b = read()
         lst[a].append(b)
      
      for i in range(10):
         lst[i].sort()
         lst[i] = [0, *lst[i]]
         # 前缀和
         for j in range(1, len(lst[i])):
             lst[i][j] += lst[i][j - 1]
      
      # 保留的个数
      k = n // 10
      
      ans = 0
      for i in range(10):
         l = len(lst[i]) - 1
         if l > k:
             ans += (lst[i][l - k])
      
      print(ans)
      
  • 试题 E: 翻转

    • 题意

    • 思路

      BFS暴力,不会剪枝,剪枝想了一种,但是没有证明正确性,所以就没有采用

    • 代码

      # AB-IN AK Lanqiao !!
      import sys, math
      from collections import Counter, deque, defaultdict
      from bisect import bisect_left, bisect_right
      from heapq import heappop, heappush, heapify
      from typing import *
      from datetime import datetime, timedelta
      
      N = int(1e6 + 10)
      INF = int(2e9)
      
      sys.setrecursionlimit(INF)
      read = lambda : map(int, input().split())
      
      class sa:
          def __init__(self, s, step):
              self.s = s
              self.step = step
          def __lt__(self, x):
              pass
      
      # ---------------divrsion line ----------------
      # BFS暴力 不会剪枝 没证明剪枝一定正确
      
      def solve():
          t = input()
          s = input()
      
          t = " " + t
          s = " " + s
      
          if t[1] != s[1] or t[-1] != s[-1]:
              return -1
      
          q = deque()
          q.appendleft(sa(s, 0))
          while len(q):
              tp = q.pop()
              s, step = tp.s, tp.step
              if s == t:
                  return step
              for i in range(2, len(s) - 1):
                  if s[i] == '0' and s[i - 1] == '1' and s[i + 1] == '1':
                      g = s[:i - 1] + "111" + s[i + 2:]
                      if g == t:
                          return step + 1
                      q.appendleft(sa(g, step + 1))
                  if s[i] == '1' and s[i - 1] == '0' and s[i + 1] == '0':
                      g = s[:i - 1] + "000" + s[i + 2:]
                      if g == t:
                          return step + 1
                      q.appendleft(sa(g, step + 1))
          return -1
      
      
      T, = read()
      for _ in range(T):
          print(solve())
      
  • 试题 F: 子矩阵

    • 题意

    • 思路

      这版是直接暴力做的
      考试最后写了一点线段树优化,只不过只维护了行和列的最小值和最大值,但感觉Python写的线段树也优化不了多少

    • 代码

      # AB-IN AK Lanqiao !!
      import sys, math
      from collections import Counter, deque, defaultdict
      from bisect import bisect_left, bisect_right
      from heapq import heappop, heappush, heapify
      from typing import *
      from datetime import datetime, timedelta
      
      N = int(1e3 + 10)
      MOD = 998244353
      INF = int(2e9)
      
      sys.setrecursionlimit(INF)
      read = lambda : map(int, input().split())
      
      class sa:
          def __init__(self, x, y):
              self.x = x
              self.y = y
          def __lt__(self, x):
              pass
      
      # ---------------divrsion line ----------------
      # RMQ 问题 可写ST表 但我忘了...
      # 暴力!
      g = [[0] * N for _ in range(N)]
      n, m, a, b = read()
      
      def func(t1, t2):
          mn, mx = INF, 0
          for i in range(t1.x, t2.x + 1):
              for j in range(t1.y, t2.y + 1):
                  mn = min(mn, g[i][j])
                  mx = max(mx, g[i][j])
          return mx * mn % MOD
      
      for i in range(1, n + 1):
          g[i][1:] = read()
      
      ans = 0
      for i in range(1, n + 1):
          for j in range(1, m + 1):
              t1 = sa(i, j)
              t2 = sa(i + a - 1, j + b - 1)
              if i + a - 1 > n or j + b - 1 > m:
                  continue
              ans = (ans + func(t1, t2)) % MOD 
      
      print(ans)
      
  • 试题 G: 阶乘的和

    • 题意

    • 思路

      还是暴力,思路就是可以把共因子都提出来,剩下的加和,从提出来的共同的因子的最大值开始,让加和除以它,直到不能除了,就是答案
      其中,用哈希表记录用过的阶乘值,预处理一些阶乘值

    • 代码

      # AB-IN AK Lanqiao !!
      import sys, math
      from collections import Counter, deque, defaultdict
      from bisect import bisect_left, bisect_right
      from heapq import heappop, heappush, heapify
      from typing import *
      from datetime import datetime, timedelta
      
      N = int(1e5 + 10)
      INF = int(2e9)
      
      sys.setrecursionlimit(INF)
      read = lambda : map(int, input().split())
      
      class sa:
         def __init__(self, x, y):
             self.x = x
             self.y = y
         def __lt__(self, x):
             pass
      
      # ---------------divrsion line ----------------
      # 暴力!
      # 预处理1 ~ 5000阶乘
      dd = Counter()
      cnt = 1
      for i in range(1, 5000):
         cnt *= i
         dd[i] = cnt
      # ---------------------------------------------
      a = [0] * N
      
      n, = read()
      a[1:] = list(read())
      d = Counter()
      
      base = min(a[1:])
      ans = 0
      for i in range(1, n + 1):
         tmp = 1
         if a[i] < 5000:
             d[a[i]] = dd[a[i]] // dd[base]
         elif d[a[i]] == 0:
             for j in range(a[i], base, -1):
                 tmp *= j
             d[a[i]] = tmp
         ans += d[a[i]]
      
      while True:
         if ans == 1 or ans % (base + 1) != 0:
             break
         base += 1
         ans //= base
      
      print(base)
      
  • 试题 H: 奇怪的数

    • 题意

    • 思路

      还是暴力DFS
      相当于搜满足条件的n位数,直接搜每一位即可,因为奇数位为奇数,偶数位为偶数
      优化就是每次搜每一位的时候,和前面的四位数加和,判断是否小于等于m,如果不满足就直接不搜了

    • 代码

      # AB-IN AK Lanqiao !!
      import sys, math
      from collections import Counter, deque, defaultdict
      from bisect import bisect_left, bisect_right
      from heapq import heappop, heappush, heapify
      from typing import *
      from datetime import datetime, timedelta
      
      N = int(1e6 + 10)
      INF = int(2e9)
      MOD = 998244353
      
      sys.setrecursionlimit(INF)
      read = lambda : map(int, input().split())
      
      class sa:
          def __init__(self, x, y):
              self.x = x
              self.y = y
          def __lt__(self, x):
              pass
      
      # ---------------divrsion line ----------------
      # 感觉像数位dp,先打DFS暴力
      # 想不出递推式 就优化暴力吧
      
      n, m = read()
      
      ji = ["1", "3", "5", "7", "9"]
      ou = ["0", "2", "4", "6", "8"]
      stji, stou = [0] * 5, [0] * 5
      ans = 0
      
      def dfs(s, d):
          global ans
          if d == n + 1:
              ans = (ans + 1) % MOD
              return
      
          for i in range(5):
              if d % 2 == 1:
                  cnt = int(ji[i])
                  for j in range(max(1, d - 4), d):
                      cnt += int(s[j])
                  if cnt <= m:
                      dfs(s + ji[i], d + 1)
              if d % 2 == 0:
                  cnt = int(ou[i])
                  for j in range(max(1, d - 4), d):
                      cnt += int(s[j])
                  if cnt <= m:
                      dfs(s + ou[i], d + 1)
          return  
      
      
      dfs(" ", 1)
      print(ans % MOD)
      
  • 试题 I: 子树的大小

    • 题意

    • 思路

      没时间想了,感觉暴力都很麻烦

    • 代码

  • 试题 J: 反异或 01 串

    • 题意

    • 思路

      没时间想了,就特判了几种情况

    • 代码

      # AB-IN AK Lanqiao !!
      import sys, math
      from collections import Counter, deque, defaultdict
      from bisect import bisect_left, bisect_right
      from heapq import heappop, heappush, heapify
      from typing import *
      from datetime import datetime, timedelta
      
      N = int(1e6 + 10)
      INF = int(2e9)
      
      sys.setrecursionlimit(INF)
      read = lambda : map(int, input().split())
      
      class sa:
          def __init__(self, x, y):
              self.x = x
              self.y = y
          def __lt__(self, x):
              pass
      
      # ---------------divrsion line ----------------
      # 骗分
      
      def solve(s):
          d = Counter(s)
          if len(s) == d['0']:
              return 0
          if len(s) == d['1']:
              return len(s) // 2
          if s == "00111011":
              return 3
          return d['1']
          
      s = input()
      
      print(solve(s))
      

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