Question

Given two strings s and t, both consisting of lowercase English letters and digits, your task is to calculate how many ways exactly one digit could be removed from one of the strings so that s is lexicographically smaller than t after the removal. Note that we are removing only a single instance of a single digit, rather than all instances (eg: removing 1 from the string a11b1c could result in a1b1c or a11bc, but not abc).

Also note that digits are considered lexicographically smaller than letters.

Answer 1

To solve this, you can go through each letter in both words and see if they are the same. If you see a number in one of the strings, you can choose to remove the number from the first string or from the second string. Count how many times the first word is smaller than the second word.

The Python function that implements this logic:

def count_ways_to_remove_digit(s, t):

result = 0

for i in range(len(s)):

if s[i].isdigit():

# Case 1: Remove digit from s

modified_s = s[:i] + s[i+1:]

if modified_s < t:

result += 1

for i in range(len(t)):

if t[i].isdigit():

# Case 2: Remove digit from t

modified_t = t[:i] + t[i+1:]

if s < modified_t:

result += 1

return result

# Example usage:

s = "a11b1c"

t = "a11bc"

result = count_ways_to_remove_digit(s, t)

print(result)

So, in the above example, The count_ways_to_remove_digit function takes two words, s and t, and tells you how many ways you can remove a number from s so that it becomes smaller than t. The example words are "a11b1c" and "a11bc. "

So, based on the example, the answer is 2 because you can take away the number "1" in two different ways: either from the first word ("a1b1c") or from the second word ("a11bc").