Codeforces Round #445 (Div. 2, based on Technocup 2018 Elimination Round 3)

A. ACM ICPC

题意

问你能否把6个人按照分数平均分成2支队

题解

暴力看有没有3个人的分数加起来正好一半

 1 a = []
 2 sum = 0
 3 line = input().split()
 4 for i in range(6):
 5     a.append(int(line[i]))
 6     sum += a[i]
 7     pass
 8 half = sum // 2
 9 if sum != half * 2:
10     print('NO')
11     pass
12 else:
13     ok = 0
14     for i in range(6):
15         for j in range(i + 1, 6):
16             for k in range(j + 1, 6):
17                 if a[i] + a[j] + a[k] == half:
18                     ok = 1
19                     pass
20                 continue
21             continue
22         continue
23     if ok == 1:
24         print('YES')
25         pass
26     else:
27         print('NO')
28         pass
View Code

B. Vlad and Cafes

题意

问Vlad去过的咖啡厅里, 没去时间最久的一个

题解

从后往前一个一个标记, 找到最后一个标记上的

 1 vis = [0 for i in range(200005)]
 2 n = int(input())
 3 a = []
 4 line = input().split()
 5 for i in range(n):
 6     a.append(int(line[i]))
 7     pass
 8 ans = 0
 9 for i in range(n - 1, -1, -1):
10     if vis[a[i]] == 1:
11         continue
12     else:
13         vis[a[i]] = 1
14         ans = a[i]
15         continue
16     continue
17 print(ans)
View Code

C. Petya and Catacombs

题意

略

题解

把"当前房间"和"当前房间记录的ti时间到的房间"连起来, 形成一棵树

求这棵树的叶子结点的个数

 1 n = int(input())
 2 vis = [0 for i in range(n + 1)]
 3 line = input().split()
 4 for i in range(n):
 5     vis[int(line[i])] = 1
 6     continue
 7 ans = 0
 8 for i in range(n + 1):
 9     if vis[i] == 0:
10         ans += 1
11         continue
12     continue
13 print(ans)
View Code

D.

E.

F.

posted @ 2017-11-16 22:46  HexSix  阅读(224)  评论(0)  编辑  收藏  举报