結果

問題 No.3056 Disconnected Coloring
コンテスト
ユーザー lif4635
提出日時 2025-03-14 21:33:18
言語 PyPy3
(7.3.15)
結果
RE  
実行時間 -
コード長 4,468 bytes
コンパイル時間 311 ms
コンパイル使用メモリ 82,660 KB
実行使用メモリ 109,476 KB
最終ジャッジ日時 2025-03-14 21:33:35
合計ジャッジ時間 14,657 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge1
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 2
other AC * 25 WA * 2 RE * 7
権限があれば一括ダウンロードができます

ソースコード

diff # 

# input
import sys
input = sys.stdin.readline
II = lambda : int(input())
MI = lambda : map(int, input().split())
LI = lambda : [int(a) for a in input().split()]
SI = lambda : input().rstrip()
LLI = lambda n : [[int(a) for a in input().split()] for _ in range(n)]
LSI = lambda n : [input().rstrip() for _ in range(n)]
MI_1 = lambda : map(lambda x:int(x)-1, input().split())
LI_1 = lambda : [int(a)-1 for a in input().split()]

def graph(n:int, m:int, dir:bool=False, index:int=-1) -> list[set[int]]:
    edge = [set() for i in range(n+1+index)]
    for _ in range(m):
        a,b = map(int, input().split())
        a += index
        b += index
        edge[a].add(b)
        if not dir:
            edge[b].add(a)
    return edge

def graph_w(n:int, m:int, dir:bool=False, index:int=-1) -> list[set[tuple]]:
    edge = [set() for i in range(n+1+index)]
    for _ in range(m):
        a,b,c = map(int, input().split())
        a += index
        b += index
        edge[a].add((b,c))
        if not dir:
            edge[b].add((a,c))
    return edge

mod = 998244353
inf = 1001001001001001001
ordalp = lambda s : ord(s)-65 if s.isupper() else ord(s)-97
ordallalp = lambda s : ord(s)-39 if s.isupper() else ord(s)-97
yes = lambda : print("Yes")
no = lambda : print("No")
yn = lambda flag : print("Yes" if flag else "No")
def acc(a:list[int]):
    sa = [0]*(len(a)+1)
    for i in range(len(a)):
        sa[i+1] = a[i] + sa[i]
    return sa

prinf = lambda ans : print(ans if ans < 1000001001001001001 else -1)
alplow = "abcdefghijklmnopqrstuvwxyz"
alpup = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
alpall = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
URDL = {'U':(-1,0), 'R':(0,1), 'D':(1,0), 'L':(0,-1)}
DIR_4 = [[-1,0],[0,1],[1,0],[0,-1]]
DIR_8 = [[-1,0],[-1,1],[0,1],[1,1],[1,0],[1,-1],[0,-1],[-1,-1]]
DIR_BISHOP = [[-1,1],[1,1],[1,-1],[-1,-1]]
prime60 = [2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59]
sys.set_int_max_str_digits(0)
sys.setrecursionlimit(10**6)
# import pypyjit
# pypyjit.set_param('max_unroll_recursion=-1')

from collections import defaultdict,deque
from heapq import heappop,heappush
from bisect import bisect_left,bisect_right
DD = defaultdict
BSL = bisect_left
BSR = bisect_right


class DSU:
    def __init__(self, n, fix_leader = False):
        self.n = n
        self.par = [*range(n)]
        self.siz = [1] * n
        self.fix_leader = fix_leader

    def leader(self, a):
        while self.par[a] != a:
            self.par[a] = a = self.par[self.par[a]]
        return a

    def merge(self, a, b):
        a = self.leader(a)
        b = self.leader(b)
        if a == b: return a
        if self.fix_leader or self.siz[a] > self.siz[b]:
            self.siz[a] += self.siz[b]
            self.par[b] = a
            return a
        else:
            self.siz[b] += self.siz[a]
            self.par[a] = b
            return b

    def same(self, a, b):
        return self.leader(a) == self.leader(b)
    
    def size(self, a):
        return self.siz[self.leader(a)]
    
    def groups(self):
        res = [[] for i in range(self.n)]
        for i in range(self.n):
            res[self.leader(i)].append(i)
        res2 = []
        for i in range(self.n):
            if len(res[i]) > 0:
                res2.append(res[i])
        return res2

n,m = MI()
edge = []
uf0 = DSU(n)
ufn = DSU(n)
c0 = 0
cn = 0
for i in range(m):
    u,v = MI_1()
    edge.append((u, v))
    if u == 0:
        c0 += 1
    if v == n-1:
        cn += 1
    
    if u != 0:
        uf0.merge(u, v)
    if v != n-1:
        ufn.merge(u, v)
    
    # 直接の辺がある
    if u == 0 and v == n-1:
        print(-1)
        exit()

if m % 2 == 1:
    print(-1)
    exit()

ans = [-1]*m
if c0 <= m//2 and cn <= m//2:
    
    for i in range(m):
        u,v = edge[i]
        if u == 0:
            ans[i] = 1
        if v == n-1:
            ans[i] = 0 
    
elif c0 > m //2:
    for i in range(m):
        if u == 0:
            if uf.same(v, n-1):
                ans[i] = 1
        if v == n-1:
            ans[i] = 0
elif cn > m//2:
    for i in range(m):
        if u == 0:
            ans[i] = 1
        if v == n-1:
            if uf.same(0, u):
                ans[i] = 0

# 決まっていないところを決める
c = m//2 - ans.count(1)
for i in range(m):
    if ans[i] == -1:
        if c != 0:
            ans[i] = 1
            c -= 1
        else:
            ans[i] = 0

ans = ["B" if f else "R" for f in ans]
print(*ans, sep = "")
0