Package g1801_1900.s1830_minimum_number_of_operations_to_make_string_sorted

Class Solution

java.lang.Object
g1801_1900.s1830_minimum_number_of_operations_to_make_string_sorted.Solution
public class Solution extends Object
1830 - Minimum Number of Operations to Make String Sorted\. Hard You are given a string `s` ( **0-indexed** ). You are asked to perform the following operation on `s` until you get a sorted string: 1. Find **the largest index** `i` such that `1 <= i < s.length` and `s[i] < s[i - 1]`. 2. Find **the largest index** `j` such that `i <= j < s.length` and `s[k] < s[i - 1]` for all the possible values of `k` in the range `[i, j]` inclusive. 3. Swap the two characters at indices `i - 1` and `j`. 4. Reverse the suffix starting at index `i`. Return _the number of operations needed to make the string sorted._ Since the answer can be too large, return it **modulo** 109 + 7. **Example 1:** **Input:** s = "cba" **Output:** 5 **Explanation:** The simulation goes as follows: Operation 1: i=2, j=2. Swap s[1] and s[2] to get s="cab", then reverse the suffix starting at 2. Now, s="cab". Operation 2: i=1, j=2. Swap s[0] and s[2] to get s="bac", then reverse the suffix starting at 1. Now, s="bca". Operation 3: i=2, j=2. Swap s[1] and s[2] to get s="bac", then reverse the suffix starting at 2. Now, s="bac". Operation 4: i=1, j=1. Swap s[0] and s[1] to get s="abc", then reverse the suffix starting at 1. Now, s="acb". Operation 5: i=2, j=2. Swap s[1] and s[2] to get s="abc", then reverse the suffix starting at 2. Now, s="abc". **Example 2:** **Input:** s = "aabaa" **Output:** 2 **Explanation:** The simulation goes as follows: Operation 1: i=3, j=4. Swap s[2] and s[4] to get s="aaaab", then reverse the substring starting at 3. Now, s="aaaba". Operation 2: i=4, j=4. Swap s[3] and s[4] to get s="aaaab", then reverse the substring starting at 4. Now, s="aaaab". **Constraints:** * `1 <= s.length <= 3000` * `s` consists only of lowercase English letters.

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • makeStringSorted

      public int makeStringSorted(String s)