#1177

Can Make Palindrome from Substring

medium · verified · 41.4% accepted · 876 likes · top 22%

array · hash table · string · bit manipulation · prefix sum

Description

You are given a string s and array queries where queries[i] = [lefti, righti, ki]. We may rearrange the substring s[lefti...righti] for each query and then choose up to ki of them to replace with any lowercase English letter.

If the substring is possible to be a palindrome string after the operations above, the result of the query is true. Otherwise, the result is false.

Return a boolean array answer where answer[i] is the result of the i^th query queries[i].

Note that each letter is counted individually for replacement, so if, for example s[lefti...righti] = "aaa", and ki = 2, we can only replace two of the letters. Also, note that no query modifies the initial string s.

Example 1:

Input: s = "abcda", queries = [[3,3,0],[1,2,0],[0,3,1],[0,3,2],[0,4,1]]

Output: [true,false,false,true,true]

Explanation:

queries[0]: substring = "d", is palidrome.

queries[1]: substring = "bc", is not palidrome.

queries[2]: substring = "abcd", is not palidrome after replacing only 1 character.

queries[3]: substring = "abcd", could be changed to "abba" which is palidrome. Also this can be changed to "baab" first rearrange it "bacd" then replace "cd" with "ab".

queries[4]: substring = "abcda", could be changed to "abcba" which is palidrome.

Example 2:

Input: s = "lyb", queries = [[0,1,0],[2,2,1]]

Output: [false,true]

Solution