29 lines
518 B
Python
29 lines
518 B
Python
from sys import stdin
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n=int(stdin.readline().rstrip())
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m=int(stdin.readline().rstrip())
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arr=[[0]*n for _ in range(n)]
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for _ in range(m):
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a,b=map(int,stdin.readline().rstrip().split())
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a-=1
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b-=1
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arr[a][b]=arr[b][a]=1
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visit=[0 for _ in range(n)]
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visit[0]=1
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next=[]
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i=0
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cnt=0
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while True:
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for j in range(n):
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if visit[j]==0 and arr[i][j]==1:
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cnt+=1
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visit[j]=1
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next.append(j)
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if len(next)==0:
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break
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else:
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i=next.pop()
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print(cnt) |