AtCoder Beginner Contest 132をといてみた

A - Fifty-Fifty

入力例

ASSA

import collections
list = list(input())
c = collections.Counter(list)
count = 0

for k,v in c.items():
    if v == 2:
        count = count +1

if count == 2:
    print("Yes")
else:
    print("No")

B - Ordinary Number

入力例

5
1 3 5 4 2

C - Divide the Problems

6
9 1 4 4 6 7

N = int(input())
numbers = list(map(int, input().split()))

result = 0

for count in range(N-2):
    sliced_list = numbers[:3]
    if min(sliced_list) != sliced_list[1] and max(sliced_list) != sliced_list[1]:
        result = result + 1
    numbers.pop(0)
print(result)

N = int(input())
levels = list(map(int, input().split()))
#print(levels)
levels.sort()
#print(levels)

divid_number = int(N/2)
#print(levels[divid_number-1])
#print(levels[divid_number])
print(levels[divid_number]-levels[divid_number-1])

D - Blue and Red Balls

入力例

5 3

回答例

きっと場合分けを頑張るんだろうなと思ったけどボールの数が多くなれば多くなるほどどうすれば良いのかわからなくて困っていた

import math
N, K = map(int, input().split())

print((N-K+1)%(1000000000+7))
print(math.factorial(N-K+1)%(1000000000+7))
print(math.factorial(N-K-2+1)%(1000000000+7))