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())
F = [[] for _ in range(N)]
B = [[] for _ in range(N)]

for _ in range(M):
    a, b = map(int, input().split())
    a, b = a - 1, b - 1
    F[a].append(b)
    F[b].append(a)

print(F)

for _ in range(K):
    c, d = map(int, input().split())
    c, d = c - 1, d - 1
    B[c].append(d)
    B[d].append(c)


class UnionFind:
    def __init__(self, n):
        
        self.par = [i for i in range(n)]
        
        self.rank = [0] * n
        
        self.size = [1] * n

    
    def find(self, x):
        
        if self.par[x] == x:
            return x
        
        else:
            
            self.par[x] = self.find(self.par[x])
            return self.par[x]

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

        if x == y:
            return
        
        if self.rank[x] < self.rank[y]:
            self.par[x] = y
            self.size[y] += self.size[x]
        else:
            self.par[y] = x
            self.size[x] += self.size[y]
            
            if self.rank[x] == self.rank[y]:
                self.rank[x] += 1

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

    
    def all_find(self):
        for n in range(len(self.par)):
            self.find(n)


UF = UnionFind(N)
for iam in range(N):
    for friend in F[iam]: 
        UF.union(iam, friend) 

ans = [UF.size[UF.find(iam)] - 1 for iam in range(N)] 

for iam in range(N):
    ans[iam] -= len(F[iam]) 

for iam in range(N):
    for block in B[iam]:
        if UF.same(iam, block): 
            ans[iam] -= 1

print(*ans, sep=' ')


N, M, K = map(int, input().split())
F = [[] for _ in range(N)]
B = [[] for _ in range(N)]

for _ in range(M):
    a, b = map(int, input().split())
    a, b = a - 1, b - 1
    F[a].append(b)
    F[b].append(a)

for _ in range(K):
    c, d = map(int, input().split())
    c, d = c - 1, d - 1
    B[c].append(d)
    B[d].append(c)


class UnionFind:
    def __init__(self, n):
        
        self.par = [i for i in range(n)]
        
        self.rank = [0] * n
        
        self.size = [1] * n

    
    def find(self, x):
        
        if self.par[x] == x:
            return x
        
        else:
            
            self.par[x] = self.find(self.par[x])
            return self.par[x]

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

        if x == y:
            return
        
        if self.rank[x] < self.rank[y]:
            self.par[x] = y
            self.size[y] += self.size[x]
        else:
            self.par[y] = x
            self.size[x] += self.size[y]
            
            if self.rank[x] == self.rank[y]:
                self.rank[x] += 1

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


UF = UnionFind(N)
for iam in range(N):
    for friend in F[iam]: 
        UF.union(iam, friend) 

ans = [UF.size[UF.find(iam)] - 1 for iam in range(N)] 

for iam in range(N):
    ans[iam] -= len(F[iam]) 

for iam in range(N):
    for block in B[iam]:
        if UF.same(iam, block): 
            ans[iam] -= 1

print(*ans, sep=' ')


Verdicts: Wrong Answer

Accepted