CODEWITHSUNDEEP
listpython-3.x
tmj
tmj

Reputation: 1858

List index out of range ? It should not be

def trav(r,c):
  #print("(",r,",",c,")")
  ch = a[r+1][c+1]

  lu= a[r][c]
  #print(lu)
  u = a[r][c+1]
  #print(u)
  ru= a[r][c+2]
  #print(ru)

  l = a[r+1][c]
  #print(l)
  r = a[r+1][c+2]
  #print(r)

  ld= a[r+2][c]
  #print(ld)
  d = a[r+2][c+1]
  #print(d)
  rd= a[r+2][c+2]
  #print(rd)

  a1 = a2 = a3 = a4 = a5 = a6 = a7 = a8 = 0

  if(ch == lu-1):
    a1 = trav(r-1,c-1)

  if(ch == u-1):
    a2 = trav(r-1,c)

  if(ch == ru-1):
    a3 = trav(r-1,c+1)

  if(ch == l-1):
    a4 = trav(r,c-1)

  if(ch == r-1):
    a5 = trav(r,c+1)

  if(ch == ld-1):
    a6 = trav(r+1,c-1)

  if(ch == d-1):
    a7 = trav(r+1,c)

  if(ch == rd-1):
    a8 = trav(r+1,c+1)

  return max(a1,a2,a3,a4,a5,a6,a7,a8) + 1


while(1):
  row,col = [int(x) for x in input().split(" ")]

  if(row == 0):
    break

  a = []
  for index in range(10):
    a.append([])
    for jindex in range(10):
      a[index].append('a')

  b = []
  for index in range(row):
    str = input()
    for jindex in range(col):
      a[index+1][jindex + 1] = ord(str[jindex])
      if(str[jindex] == 'A'):
        b.append([index,jindex])

  #print (a)
  #print (b)

  ans = max([trav(x[0],x[1]) for x in b])

  print(ans)

The code is generating the following error 

 Traceback (most recent call last):   File "C:/Users/DELL/Desktop/ABCPATH.py", line 80, in <module>
    ans = max([trav(x[0],x[1]) for x in b])   File "C:/Users/DELL/Desktop/ABCPATH.py", line 80, in <listcomp>
    ans = max([trav(x[0],x[1]) for x in b])   File "C:/Users/DELL/Desktop/ABCPATH.py", line 17, in trav
    ld= a[r+2][c] IndexError: list index out of range

But according to me it should not, and as I am extremely new to python , I am not able to debug it. Please help

sample input taken: 

4 3
ABC
CFG
BDH
ABC

Upvotes: 0

Views: 261

Answers (1)

bobrobbob
bobrobbob

Reputation: 1281

It has to break

r = a[r+1][c+2]

you're reassigning the value of 'r' in that line. please also note that you shouldn't name your string "str" as it is the name of the python string module and you won't be able to use it.

Upvotes: 1

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