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ABC402振り返り

Last updated at Posted at 2025-04-19

前回の振り返り

今日はABC開催日だったので参加結果を振り返る
https://atcoder.jp/contests/abc402

今週はA,B,Cの3完(0ペナ)

A

内包記法でフィルターする

ソースコード

main.py
from bisect import bisect_left, bisect_right, insort_left, insort_right
from collections import defaultdict, Counter, deque
from functools import reduce, lru_cache
from itertools import product, accumulate, groupby, combinations
import sys
import os
def rI(): return int(sys.stdin.readline().rstrip())
def rLI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def rI1(): return (int(sys.stdin.readline().rstrip())-1)
def rLI1(): return list(map(lambda a:int(a)-1,sys.stdin.readline().rstrip().split()))
def rS(): return sys.stdin.readline().rstrip()
def rLS(): return list(sys.stdin.readline().rstrip().split())
IS_LOCAL = int(os.getenv("ATCODER", "0"))==0
err = (lambda *args, **kwargs: print(*args, **kwargs, file=sys.stderr)) if IS_LOCAL else (lambda *args, **kwargs: None)

def main():
    S = rS()
    ans = [s for s in S if ord("A") <= ord(s) <= ord("Z")]
    print("".join(ans))
    
if __name__ == '__main__':
    main()

B

queueを使った練習問題ですね。

ソースコード

main.py
from bisect import bisect_left, bisect_right, insort_left, insort_right
from collections import defaultdict, Counter, deque
from functools import reduce, lru_cache
from itertools import product, accumulate, groupby, combinations
import sys
import os
def rI(): return int(sys.stdin.readline().rstrip())
def rLI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def rI1(): return (int(sys.stdin.readline().rstrip())-1)
def rLI1(): return list(map(lambda a:int(a)-1,sys.stdin.readline().rstrip().split()))
def rS(): return sys.stdin.readline().rstrip()
def rLS(): return list(sys.stdin.readline().rstrip().split())
IS_LOCAL = int(os.getenv("ATCODER", "0"))==0
err = (lambda *args, **kwargs: print(*args, **kwargs, file=sys.stderr)) if IS_LOCAL else (lambda *args, **kwargs: None)

def main():
    Q = rI()
    q = deque()
    for _ in range(Q):
        query = rLI()
        if query[0] == 1:
            q.append(query[1])
        elif query[0] == 2:
            print(q.popleft())
    
if __name__ == '__main__':
    main()

C

入っている食材をキーにした配列を用意して

克服した食材をそれぞれの料理に除外する。
簡略化のために数だけを操作する。

0になったらすべて克服したので加算

ソースコード

main.py
from bisect import bisect_left, bisect_right, insort_left, insort_right
from collections import defaultdict, Counter, deque
from functools import reduce, lru_cache
from itertools import product, accumulate, groupby, combinations
import sys
import os
def rI(): return int(sys.stdin.readline().rstrip())
def rLI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def rI1(): return (int(sys.stdin.readline().rstrip())-1)
def rLI1(): return list(map(lambda a:int(a)-1,sys.stdin.readline().rstrip().split()))
def rS(): return sys.stdin.readline().rstrip()
def rLS(): return list(sys.stdin.readline().rstrip().split())
IS_LOCAL = int(os.getenv("ATCODER", "0"))==0
err = (lambda *args, **kwargs: print(*args, **kwargs, file=sys.stderr)) if IS_LOCAL else (lambda *args, **kwargs: None)

def main():
    N, M = rLI()
    # S = rS()
    # A = []
    K = []
    Bi = defaultdict(list)   
    for i in range(M):
        k, *a = rLI()
        K.append(k)
        # A.append(set(a))
        for c in a:
            Bi[c].append(i)
    B = rLI()
    ans = 0
    for b in B:
        for i in Bi[b]:
            # A[i].remove(b)
            K[i] -= 1
            if K[i] == 0:
                ans += 1
        print(ans)
    
if __name__ == '__main__':
    main()

D

幾何的な問題はすぐ飛ばしちゃう

E

動的計画法したいけど、
同じ問題を2回以上提出する場合どうすればいいのかわからなくて諦めた

F

全探索したけど遅すぎて
全然改善できなかった

G

Fに沼ってノータッチ

感想

安心と信頼の3完
いつも通りすぎてなにも感想が出ない

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