{ "data": { "question": { "questionId": "3638", "questionFrontendId": "3389", "boundTopicId": null, "title": "Minimum Operations to Make Character Frequencies Equal", "titleSlug": "minimum-operations-to-make-character-frequencies-equal", "content": "

You are given a string s.

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A string t is called good if all characters of t occur the same number of times.

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You can perform the following operations any number of times:

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Note that you cannot change 'z' to 'a' using the third operation.

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Return the minimum number of operations required to make s good.

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Example 1:

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Input: s = "acab"

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Output: 1

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Explanation:

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We can make s good by deleting one occurrence of character 'a'.

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Example 2:

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Input: s = "wddw"

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Output: 0

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Explanation:

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We do not need to perform any operations since s is initially good.

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Example 3:

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Input: s = "aaabc"

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Output: 2

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Explanation:

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We can make s good by applying these operations:

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\n\n

 

\n

Constraints:

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How do the described operations change occ?", "We have three types of operations: increase any occ[x] by 1, decrease any occ[x] by 1, or decrease any occ[x] by 1 and simultaneously increase occ[x + 1] by 1 at the same time. To make s good, we need to make occ good. occ is good if and only if every occ[x] equals either 0 or some constant c.", "If you know the value of c, how can you calculate the minimum operations required to make occ good?", "Observation 1: It is never optimal to apply the third type of operation (simultaneous decrease and increase) on two continuous elements occ[x] and occ[x + 1]. Instead, we can decrease occ[x] by 1 then increase occ[x + 2] by 1 to achieve the same effect.", "Observation 2: It is never optimal to increase an element of occ then decrease it, or vice versa.", "Use dynamic programming where dp[i] is the minimum number of operations required to make occ[0..i] good. 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Kotlin 1.9.0.

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PHP 8.2.

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