第二题80%提示越界？ import sys def getExtend(matrix,i,j,mylist):     if i-1>=0:         if matrix[i-1][j]==1 and [i-1,j] not in mylist:             mylist.append([i-1,j])     if i+1<=n-1:         if matrix[i+1][j]==1 and [i+1,j] not in mylist:             mylist.append([i+1,j])     if j-1>=0:         if matrix[i][j-1]==1 and [i,j-1] not in mylist:             mylist.append([i,j-1])     if j+1<=n-1:         if matrix[i][j+1]==1 and [i,j+1] not in mylist:             mylist.append([i,j+1])     return mylist s=sys.stdin.readline().strip() data=[] while s != '':     s=list(map(int,s.split()))     data.append(s)     s=sys.stdin.readline().strip() n=data[0][0] mylist=[] value=2 matrix=data[1:] for i in range(n):     for j in range(n):         if matrix[i][j]==1:             matrix[i][j]=value             mylist=getExtend(matrix,i,j,mylist)             while mylist != []:                 [p,q]=mylist.pop()                 matrix[p][q]=value                 mylist=getExtend(matrix,p,q,mylist)             value+=1 print(value-2)