ABC解説

Toyota Programming Contest 2023 Spring Qual A(AtCoder Beginner Contest 288)

A. Many A+B Problems

import sys


def solve():
    input = sys.stdin.readline
    mod = 10 ** 9 + 7
    n = int(input().rstrip('\n'))
    for i in range(n):
        a, b = list(map(int, input().rstrip('\n').split()))
        print(a + b)

if __name__ == '__main__':
    solve()

B. Qualification Contest

import sys


def solve():
    input = sys.stdin.readline
    mod = 10 ** 9 + 7
    n, k = list(map(int, input().rstrip('\n').split()))
    print(*sorted([str(input().rstrip('\n')) for _ in range(k)]), sep="\n")


if __name__ == '__main__':
    solve()

C. Don’t be cycle

import sys


class AlgUnionFind():
    def __init__(self, n):
        self.n = n
        self.parents = [-1] * n

    def find(self, x):
        if self.parents[x] < 0:
            return x
        else:
            self.parents[x] = self.find(self.parents[x])
            return self.parents[x]

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)

        if x == y:
            return

        if self.parents[x] > self.parents[y]:
            x, y = y, x

        self.parents[x] += self.parents[y]
        self.parents[y] = x

    def size(self, x):
        return -self.parents[self.find(x)]

    def same(self, x, y):
        return self.find(x) == self.find(y)

    def members(self, x):
        root = self.find(x)
        return [i for i in range(self.n) if self.find(i) == root]

    def roots(self):
        return [i for i, x in enumerate(self.parents) if x < 0]

    def group_count(self):
        return len(self.roots())

    def all_group_members(self):
        return {r: self.members(r) for r in self.roots()}

    def __str__(self):
        return '\n'.join('{}: {}'.format(r, self.members(r)) for r in self.roots())


def solve():
    input = sys.stdin.readline
    mod = 10 ** 9 + 7
    n, m = list(map(int, input().rstrip('\n').split()))
    uf = AlgUnionFind(n)
    ans = 0
    for i in range(m):
        a, b = list(map(int, input().rstrip('\n').split()))
        if not uf.same(a-1, b-1):
            uf.union(a-1, b-1)
        else:
            ans += 1
    print(ans)


if __name__ == '__main__':
    solve()

-ABC解説