Company-Wise Interview Questions

Given a string s consisting of lowercase English letters. Perform the following operation:

Select any non-empty substring then replace every letter of the substring with the preceding letter of the English alphabet. For example, 'b' is converted to 'a', and 'a' is converted to 'z'.

Return the lexicographically smallest string after performing the operation.

Example 1:

Input: s = "cbabc"

Output: "baabc"

Explanation:

Perform the operation on the substring starting at index 0, and ending at index 1 inclusive.

Example 2:

Input: s = "aa"

Output: "az"

Explanation:

Perform the operation on the last letter.

Example 3:

Input: s = "acbbc"

Output: "abaab"

Explanation:

Perform the operation on the substring starting at index 1, and ending at index 4 inclusive.

Example 4:

Input: s = "leetcode"

Output: "kddsbncd"

Explanation:

Perform the operation on the entire string.

Constraints:

Hint 1

When a character is replaced by the one that comes before it on the alphabet, it makes the string lexicographically smaller, except for ‘a'.

Hint 2

Find the leftmost substring that doesn’t contain the character 'a' and change all characters in it.

Acceptance

34.6%

Submissions

102,871

Accepted

35,579

2828. Lexicographically Smallest String After Substring Operation