LeetCode-in-Java

3085. Minimum Deletions to Make String K-Special

Medium

You are given a string word and an integer k.

We consider word to be k-special if |freq(word[i]) - freq(word[j])| <= k for all indices i and j in the string.

Here, freq(x) denotes the frequency of the character x in word, and |y| denotes the absolute value of y.

Return the minimum number of characters you need to delete to make word k-special.

Example 1:

Input: word = “aabcaba”, k = 0

Output: 3

Explanation: We can make word 0-special by deleting 2 occurrences of "a" and 1 occurrence of "c". Therefore, word becomes equal to "baba" where freq('a') == freq('b') == 2.

Example 2:

Input: word = “dabdcbdcdcd”, k = 2

Output: 2

Explanation: We can make word 2-special by deleting 1 occurrence of "a" and 1 occurrence of "d". Therefore, word becomes equal to “bdcbdcdcd” where freq('b') == 2, freq('c') == 3, and freq('d') == 4.

Example 3:

Input: word = “aaabaaa”, k = 2

Output: 1

Explanation: We can make word 2-special by deleting 1 occurrence of "b". Therefore, word becomes equal to "aaaaaa" where each letter’s frequency is now uniformly 6.

Constraints:

Solution

public class Solution {
    public int minimumDeletions(String word, int k) {
        int[] arr = new int[26];
        for (int i = 0; i < word.length(); i++) {
            arr[word.charAt(i) - 'a']++;
        }
        int min = Integer.MAX_VALUE;
        for (int value : arr) {
            if (value != 0) {
                int u = value + k;
                int res = 0;
                for (int i : arr) {
                    if (i < value) {
                        res += i;
                    } else if (i > u) {
                        res += (i - u);
                    }
                }
                min = Math.min(res, min);
            }
        }
        return min;
    }
}