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):
import sys
N,M,K=map(int,input().split())
s=[[]for i in range(N)]
tn=[0]*N
sys.setrecursionlimit(200000)
for i in range(M):
    a,b=map(int,input().split())
    s[a-1].append(b)
    s[b-1].append(a)
    tn[a-1]+=1
    tn[b-1]+=1
l=[None]*N
def hu(n,t):
    for i in s[n]:
        if l[i-1]==None:
            l[i-1]=t
            hu(i-1,t)
t=0
for i in range(N):
    if l[i]==None:
        hu(i,t)
        t+=1
c=[0]*t
for i in l:
    c[i]+=1
for i in range(K):
    a,b=map(int,input().split())
    if l[a-1]==l[b-1]:
        tn[a-1]+=1
        tn[b-1]+=1
for i in range(N):
    print(c[l[i]]-tn[i]-1,end=" ")

import sys
N,M,K=map(int,input().split())
s=[[]for i in range(N)]
tn=[0]*N
sys.setrecursionlimit(2000000)
for i in range(M):
    a,b=map(int,input().split())
    s[a-1].append(b)
    s[b-1].append(a)
    tn[a-1]+=1
    tn[b-1]+=1
l=[None]*N
def hu(n,t):
    for i in s[n]:
        if l[i-1]==None:
            l[i-1]=t
            hu(i-1,t)
t=0
for i in range(N):
    if l[i]==None:
        hu(i,t)
        t+=1
c=[0]*t
for i in l:
    c[i]+=1
for i in range(K):
    a,b=map(int,input().split())
    if l[a-1]==l[b-1]:
        tn[a-1]+=1
        tn[b-1]+=1
for i in range(N):
    print(c[l[i]]-tn[i]-1,end=" ")

import sys
N,M,K=map(int,input().split())
tn=[0]*N
l=[i for i in range(N)]
for i in range(M):
    A,B=map(lambda x:int(x)-1,input().split())
    t=B
    tn[A]+=1
    tn[B]+=1
    while 1:
        if l[t]==t:
            l[t]=l[A]
            break
        l[t],t=l[A],l[t]
ln=[0]*N
for i in range(N):
    if l[i]!=i:
        c=[i]
        t=l[i]
        while 1:
            if l[t]==t:
                for j in c:
                    l[j]=t
                break
            t=l[t]
        ln[t]+=1
    else:
        ln[i]+=1
for i in range(K):
    C,D=map(lambda x: int(x)-1,input().split())
    if l[C]==l[D]:
        tn[C]+=1
        tn[D]+=1
for i in range(N):
    print(ln[l[i]]-tn[i]-1,end=" ")


import sys
def input():
    return sys.stdin.readline()[:-1]
sys.setrecursionlimit(200000)
class uf:
    def __init__(self,n):
        self.n=n
        self.l=[-1]*n
    def ro(self,n):
        if self.l[n]<0:
            return n
        r=self.ro(self.l[n])
        self.l[n]=r
        return r
    def me(self,a,b):
        ra=self.ro(a)
        rb=self.ro(b)
        if self.l[ra]>self.l[rb]:
            ra,rb=rb,ra
        if ra!=rb:
            self.l[ra]+=self.l[rb]
            self.l[rb]=ra
    def size(self,n):
        return -self.l[self.ro(n)]
    def sa(self,a,b):
        return self.ro(a)==self.ro(b)
N,M,K=map(int,input().split())
u=uf(N)
l=[-1]*N
for i in range(M):
    A,B=map(lambda x: int(x)-1,input().split())
    u.me(A,B)
    l[A]-=1
    l[B]-=1
for i in range(N):
    l[i]+=u.size(i)
for i in range(K):
    C,D=map(lambda x: int(x)-1,input().split())
    if u.sa(C,D):
        l[C]-=1
        l[D]-=1
print(*l)

Verdicts: Runtime Error

Runtime Error

Time Limit Exceeded

Accepted