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Largest Palindromic Number (medium)

Problem Statement

Given a string s containing 0 to 9 digits, create the largest possible palindromic number using the string characters. It should not contain leading zeroes.

A palindromic number reads the same backward as forward.

If it's not possible to form such a number using all digits of the given string, you can skip some of them.

Examples

Example 1

Input: s = "323211444"
Expected Output: "432141234"
Justification: This is the largest palindromic number that can be formed from the given digits.

Example 2

Input: s = "998877"

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D

Davide Pugliese

· 2 years ago

         TreeMap<Integer, Integer> map = new TreeMap<>((a, b) -> b - a);

        for (int i = 0; i < num.length(); i++) {
            var key = num.charAt(i) - '0';
             System.out.println("Key above is: " + key);
            map.put(key, map.getOrDefault(key, 0) + 1);
        }

        boolean odd = false;
        int k = -1;
        Deque<Character> stack = new ArrayDeque<>();
        Deque<Character> queue = new ArrayDeque<>();
        
        for (var entry: map.entrySet()) {
             var key = entry.getKey(); 
            for (int i = 0; i < entry.getValue() / 2; i++) {
                    queue.offer((char)(key + (int)'0'));
            } 
            if (entry.getValue() % 2 == 1 && odd == false) {
                
                k = key;

M

mailman14736

· 2 months ago