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Java-based LeetCode algorithm problem solutions, regularly updated

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package g1401_1500.s1487_making_file_names_unique;

// #Medium #Array #String #Hash_Table #2022_04_01_Time_36_ms_(98.46%)_Space_50.7_MB_(97.99%)

import java.util.HashMap;

/**
 * 1487 - Making File Names Unique\.
 *
 * Medium
 *
 * Given an array of strings `names` of size `n`. You will create `n` folders in your file system **such that** , at the i^th minute, you will create a folder with the name `names[i]`.
 *
 * Since two files **cannot** have the same name, if you enter a folder name that was previously used, the system will have a suffix addition to its name in the form of `(k)`, where, `k` is the **smallest positive integer** such that the obtained name remains unique.
 *
 * Return _an array of strings of length_ `n` where `ans[i]` is the actual name the system will assign to the i^th folder when you create it.
 *
 * **Example 1:**
 *
 * **Input:** names = ["pes","fifa","gta","pes(2019)"]
 *
 * **Output:** ["pes","fifa","gta","pes(2019)"]
 *
 * **Explanation:** Let's see how the file system creates folder names:
 *
 * "pes" --> not assigned before, remains "pes"
 *
 * "fifa" --> not assigned before, remains "fifa"
 *
 * "gta" --> not assigned before, remains "gta"
 *
 * "pes(2019)" --> not assigned before, remains "pes(2019)"
 *
 * **Example 2:**
 *
 * **Input:** names = ["gta","gta(1)","gta","avalon"]
 *
 * **Output:** ["gta","gta(1)","gta(2)","avalon"]
 *
 * **Explanation:** Let's see how the file system creates folder names:
 *
 * "gta" --> not assigned before, remains "gta"
 *
 * "gta(1)" --> not assigned before, remains "gta(1)"
 *
 * "gta" --> the name is reserved, system adds (k), since "gta(1)" is also reserved, systems put k = 2. it becomes "gta(2)"
 *
 * "avalon" --> not assigned before, remains "avalon"
 *
 * **Example 3:**
 *
 * **Input:** names = ["onepiece","onepiece(1)","onepiece(2)","onepiece(3)","onepiece"]
 *
 * **Output:** ["onepiece","onepiece(1)","onepiece(2)","onepiece(3)","onepiece(4)"]
 *
 * **Explanation:** When the last folder is created, the smallest positive valid k is 4, and it becomes "onepiece(4)".
 *
 * **Constraints:**
 *
 * *   1 <= names.length <= 5 * 10⁴
 * *   `1 <= names[i].length <= 20`
 * *   `names[i]` consists of lowercase English letters, digits, and/or round brackets.
**/
public class Solution {
    public String[] getFolderNames(String[] names) {
        HashMap map = new HashMap<>();
        for (int i = 0; i < names.length; i++) {
            int prefix = map.getOrDefault(names[i], 0);
            if (prefix != 0) {
                String raw = names[i];
                while (map.getOrDefault(names[i], 0) != 0) {
                    names[i] = raw + "(" + prefix + ")";
                    prefix++;
                }
                map.put(raw, prefix);
            }
            map.put(names[i], 1);
        }
        return names;
    }
}