/*
 * Copyright 2022 <NAME>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package dev.shtanko.algorithms.leetcode

import dev.shtanko.algorithms.ALPHABET_LETTERS_COUNT

/**
 * 1941. Check if All Characters Have Equal Number of Occurrences
 * link https://leetcode.com/problems/check-if-all-characters-have-equal-number-of-occurrences/
 */
fun interface AreOccurrencesEqual {
    operator fun invoke(s: String): Boolean
}

class AreOccurrencesEqualKotlin : AreOccurrencesEqual {
    override operator fun invoke(s: String): Boolean {
        val num = s.count { it == s[0] }
        for (i in 1 until s.length) {
            if (num != s.count { it == s[i] }) return false
        }
        return true
    }
}

class AreOccurrencesEqualBF : AreOccurrencesEqual {
    override operator fun invoke(s: String): Boolean {
        val fr = IntArray(ALPHABET_LETTERS_COUNT)
        s.chars().forEach { c -> fr[c - 'a'.code]++ }
        return fr.filter { f ->
            f > 0
        }.all { f ->
            f == fr.max()
        }
    }
}
