Problem: An SNS has N users - User 1, User 2, \cdots, User N.  Between these N users, there are some relationships - M _friendships_ and K _blockships_.  For each i = 1, 2, \cdots, M, there is a bidirectional friendship between User A_i and User B_i.  For each i = 1, 2, \cdots, K, there is a bidirectional blockship between User C_i and User D_i.  We define User a to be a _friend candidate_ for User b when all of the following four conditions are satisfied:    * a \neq b.   * There is not a friendship between User a and User b.   * There is not a blockship between User a and User b.   * There exists a sequence c_0, c_1, c_2, \cdots, c_L consisting of integers between 1 and N (inclusive) such that c_0 = a, c_L = b, and there is a friendship between User c_i and c_{i+1} for each i = 0, 1, \cdots, L - 1.  For each user i = 1, 2, ... N, how many friend candidates does it have?

Submission attempts (in order):
N, M, K = map(int, input().split())
AB = [list(map(int, input().split())) for _ in range(M)]
CD = [list(map(int, input().split())) for _ in range(K)]

class UnionFind():
    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())

uf_friend = UnionFind(N)

es_friend = [[] for _ in range(N)]
es_block = [[] for _ in range(N)]

for i in range(M):
    uf_friend.union(AB[i][0]-1, AB[i][1]-1)
    es_friend[AB[i][0]-1].append(AB[i][1]-1)
    es_friend[AB[i][1]-1].append(AB[i][0]-1)
for i in range(K):
    es_block[CD[i][0]-1].append(CD[i][1]-1)
    es_block[CD[i][1]-1].append(CD[i][0]-1)

ans = [0 for _ in range(N)]
for root in uf_friend.roots():
    m = uf_friend.members(root)
    l = len(uf_friend.members(root))
    for i in range(l):
        for j in range(i+1, l):
            # if m[j] not in es_friend[m[i]] and m[j] not in es_block[m[i]]:
            ans[m[i]] += 1
            ans[m[j]] += 1
print(" ".join(list(map(str, ans))))


N, M, K = map(int, input().split())
AB = [list(map(int, input().split())) for _ in range(M)]
CD = [list(map(int, input().split())) for _ in range(K)]

class UnionFind():
    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())

uf_friend = UnionFind(N)
uf_block = UnionFind(N)

es_friend = [0 for _ in range(N)]
es_block = [0 for _ in range(N)]

for i in range(M):
    uf_friend.union(AB[i][0]-1, AB[i][1]-1)
    es_friend[AB[i][0]-1] += 1
    es_friend[AB[i][1]-1] += 1
for i in range(K):
    uf_block.union(CD[i][0]-1, CD[i][1]-1)
for i in range(K):
    if uf_friend.same(CD[i][0]-1, CD[i][1]-1):
        es_block[CD[i][0]-1] += 1
        es_block[CD[i][1]-1] += 1


ans = [0 for _ in range(N)]
for i in range(N):
    ans[i] = uf_friend.size(i) - es_friend[i] - es_block[i] - 1

print(" ".join(list(map(str, ans))))


Verdicts: Wrong Answer

Accepted