Problem p02762 (python)

Fixed submission:
import sys
from collections import defaultdict, deque
 
readline = sys.stdin.readline
n, m, k = map(int, readline().split())
# ab = [list(map(int, readline().split())) for i in range(m)]
# cd = [list(map(int, readline().split())) for i in range(k)]
 
friend = [set() for i in range(n)]
not_friend = [set() for i in range(n)]
 
suggest_friends = [-1] * n
for i in range(m):
    a, b = map(int, readline().split())
    a -= 1
    b -= 1
    friend[a].add(b)
    friend[b].add(a)
    # friend[b].append(a)
for i in range(k):
    c, d = map(int, readline().split())
    c -= 1
    d -= 1
    not_friend[c].add(d)
    not_friend[d].add(c)
    # not_friend[d].append(c)
for i in range(n):
    if suggest_friends[i] != -1:
        continue
    q = deque(friend[i])
    friend_group = set(friend[i])
    while q:
        p = q.popleft()
        for f in friend[p]:
            if not(f in friend_group):
                q.append(f)
                friend_group.add(f)
    num = len(friend_group)
    for f in friend_group:
        suggest_friends[f] = num - 1 - len(friend[f] | not_friend[f] & friend_group)
 
for i in range(n):
    if suggest_friends[i] == -1:
        suggest_friends[i] = 0
print(*suggest_friends)

Buggy submission (verdict: Runtime Error):
class UF():
    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]
n,m,k=map(int,input().split())
uf=UF(n)
F=[set()for _ in range(n)]
for i in range(m):
    a,b=map(int,input().split())
    uf.union(a-1,b-1)
    F[a-1].add(b-1)
    F[b-1].add(a-1)
    B=[0 for _ in range(n)]
for i in range(k):
    c,d=map(int,input().split())
    if uf.same(c-1,d-1):
        B[c-1]-=1
        B[d-1]-=1

A=[]
for i in range(n):
    A.append(uf.size(i)-len(F[i])+B[i]-1)
print(*A)

Buggy submission (verdict: Runtime Error):
class UF():
    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())

n,m,k=map(int,input().split())
uf=UF(n)
F=[set()for _ in range(n)]
for i in range(m):
    a,b=map(int,input().split())
    uf.union(a-1,b-1)
    F[a-1].add(b-1)
    F[b-1].add(a-1)
    B=[0 for _ in range(n)]
for i in range(k):
    c,d=map(int,input().split())
    if uf.same(c-1,d-1):
        B[c-1]-=1
        B[d-1]-=1

A=[]
for i in range(n):
    A.append(uf.size(i)-1-len(F[i])+B[i])
print(*A)

Buggy submission (verdict: Runtime Error):
class UF():
    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())

n,m,k=map(int,input().split())
uf=UF(n)
F=[set()for _ in range(n)]
for i in range(m):
    a,b=map(int,input().split())
    uf.union(a-1,b-1)
    F[a-1].add(b-1)
    F[b-1].add(a-1)
    B=[0]*n
for i in range(k):
    c,d=map(int,input().split())
    if uf.same(c-1,d-1):
        B[c-1]-=1
        B[d-1]-=1

A=[]
for i in range(n):
    A.append(uf.size(i)-1-len(F[i])+B[i])
print(*A)