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

# 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.