Check out example codes for "abs(p1[1] - p2[1])Given a non-negative number represented as an array of digits, add 1 to the number ( increment the number represented by the digits ). The digits are stored such that the most significant digit is at the head of the list". It will help you in understanding the concepts better.

Code Example 1

# Python implementation for Adding one 
# to number represented by digits 
  
import math 
  
# function for adding one to number 
def incrementVector(a): 
  
    n = len(a) 
   
    # Add 1 to last digit and find carry 
    a[n-1] += 1
    carry = a[n-1]/10
    a[n-1] = a[n-1] % 10
   
    # Traverse from second last digit 
    for i in range(n-2,-1,-1): 
        if (carry == 1): 
           a[i] += 1
           carry = a[i]/10
           a[i] = a[i] % 10
          
    # If carry is 1, we need to add 
    # a 1 at the beginning of vector 
    if (carry == 1): 
      a.insert(0, 1) 
  
# driver code 
vect=[1, 7, 8, 9] 
  
incrementVector(vect) 
  
for  i in range(0, len(vect)): 
     print(vect[i] ,end= " ") 
  
# This code is contributed by Gitanjali.

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