#732303 (PyPy3) No.1813 Magical Stones

• 問題: No.1813 Magical Stones
• ユーザー: aaaaaaaaaa2230
• 提出日時: 2022-01-20 23:16:44
• 言語: PyPy3 (7.3.15)
• 結果: AC
• 実行時間: 230 ms / 2,000 ms
• コード長: 3,477 bytes
• コンパイル時間: 206 ms
• コンパイル使用メモリ: 81,920 KB
• 実行使用メモリ: 116,396 KB
• 最終ジャッジ日時: 2024-11-24 09:16:37
• 合計ジャッジ時間: 7,050 ms
• ジャッジサーバーID （参考情報）: judge4 / judge1

ファイルパターン	結果
sample	AC * 4
other	AC * 40

ソースコード

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
import sys
input = sys.stdin.readline
class SCC:
    def __init__(self,n):
        self.n = n
        self.edges = []
    def csr(self):
        self.start = [0]*(self.n+1)
        self.elist = [0]*len(self.edges)
        for e in self.edges:
            self.start[e[0]+1] += 1
        for i in range(1,self.n+1):
            self.start[i] += self.start[i-1]
        counter = self.start[:]
        for e in self.edges:
            self.elist[counter[e[0]]] = e[1]
            counter[e[0]] += 1
    def add_edge(self,u,v):
        self.edges.append((u,v))
    def scc_ids(self):
        self.csr()
        n = self.n
        now_ord = group_num = 0
        visited = []
        low = [0]*n
        order = [-1]*n
        ids = [0]*n
        parent = [-1]*n
        stack = []
        for i in range(n):
            if order[i] == -1:
                stack.append(i)
                stack.append(i)
                while stack:
                    v = stack.pop()
                    if order[v] == -1:
                        low[v] = order[v] = now_ord
                        now_ord += 1
                        visited.append(v)
                        for i in range(self.start[v],self.start[v+1]):
                            to = self.elist[i]
                            if order[to] == -1:
                                stack.append(to)
                                stack.append(to)
                                parent[to] = v
                            else:
                                low[v] = min(low[v],order[to])
                    else:
                        if low[v] == order[v]:
                            while True:
                                u = visited.pop()
                                order[u] = n
                                ids[u] = group_num
                                if u == v:
                                    break
                            group_num += 1
                        if parent[v] != -1:
                            low[parent[v]] = min(low[parent[v]],low[v])
        for i,x in enumerate(ids):
            ids[i] = group_num-1-x
        return group_num,ids
    def scc(self):
        group_num,ids = self.scc_ids()
        groups = [[] for i in range(group_num)]
        for i,x in enumerate(ids):
            groups[x].append(i)
        return groups
    
class Unionfind:
     
    def __init__(self,n):
        self.uf = [-1]*n
 
    def find(self,x):
        if self.uf[x] < 0:
            return x
        else:
            self.uf[x] = self.find(self.uf[x])
            return self.uf[x]
 
    def same(self,x,y):
        return self.find(x) == self.find(y)
 
    def union(self,x,y):
        x = self.find(x)
        y = self.find(y)
        if x == y:
            return False
        if self.uf[x] > self.uf[y]:
            x,y = y,x
        self.uf[x] += self.uf[y]
        self.uf[y] = x
        return True
 
    def size(self,x):
        x = self.find(x)
        return -self.uf[x]
n,m = map(int,input().split())
scc = SCC(n)
for i in range(m):
    a,b = [int(x)-1 for x in input().split()]
    scc.add_edge(a,b)
group = scc.scc()
groups = [0]*n
for i,g in enumerate(group):
    for j in g:
        groups[j] = i
ans = 0
    
used = [1]*len(group)
used2 = [1]*len(group)
for a,b in scc.edges:
    if groups[a] != groups[b]:
        used[groups[a]] = 0
        used2[groups[b]] = 0
ans = max(sum(used),sum(used2))
if len(used) == 1:
    ans = 0
print(ans)
 
 
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX