2075. Decode the Slanted Ciphertext

/**
 * Problem: LeetCode 2075 - Decode the Slanted Ciphertext
 * Difficulty: Medium
 * Language: Java
 * Author: CodeByTushu
 */
class Solution {
    public String decodeCiphertext(String encodedText, int rows) {
        if (rows == 1 || encodedText == null || encodedText.isEmpty()) {
            return encodedText;
        }

        int n = encodedText.length();
        int cols = n / rows;
        StringBuilder sb = new StringBuilder(n);

        for (int c = 0; c < cols; c++) {
            for (int r = 0; r < rows && c + r < cols; r++) {
                sb.append(encodedText.charAt(r * cols + (c + r)));
            }
        }

        int len = sb.length();
        while (len > 0 && sb.charAt(len - 1) == ' ') {
            len--;
        }
        sb.setLength(len);

        return sb.toString();
    }
}

"""
Problem: LeetCode 2075 - Decode the Slanted Ciphertext
Difficulty: Medium
Language: Python
Author: CodeByTushu
"""
class Solution:
    def decodeCiphertext(self, encodedText: str, rows: int) -> str:
        """
        Decodes a slanted transposition ciphertext matrix back into originalText.
        
        Time Complexity: O(N)
        Space Complexity: O(N)
        """
        if rows == 1 or not encodedText:
            return encodedText

        n = len(encodedText)
        cols = n // rows
        res = []

        for c in range(cols):
            for r in range(rows):
                if c + r >= cols:
                    break
                res.append(encodedText[r * cols + (c + r)])

        return "".join(res).rstrip(" ")

/**
 * Problem: LeetCode 2075 - Decode the Slanted Ciphertext
 * Difficulty: Medium
 * Language: C++
 * Author: CodeByTushu
 */
#include <string>

using namespace std;

class Solution {
public:
    string decodeCiphertext(string encodedText, int rows) {
        if (rows == 1 || encodedText.empty()) {
            return encodedText;
        }

        int n = encodedText.size();
        int cols = n / rows;
        string res = "";
        res.reserve(n);

        for (int c = 0; c < cols; c++) {
            for (int r = 0; r < rows && c + r < cols; r++) {
                res += encodedText[r * cols + (c + r)];
            }
        }

        while (!res.empty() && res.back() == ' ') {
            res.pop_back();
        }

        return res;
    }
};

/**
 * Problem: LeetCode 2075 - Decode the Slanted Ciphertext
 * Difficulty: Medium
 * Language: JavaScript
 * Author: CodeByTushu
 */
var decodeCiphertext = function(encodedText, rows) {
    if (rows === 1 || !encodedText) {
        return encodedText;
    }

    const n = encodedText.length;
    const cols = Math.floor(n / rows);
    const res = [];

    for (let c = 0; c < cols; c++) {
        for (let r = 0; r < rows && c + r < cols; r++) {
            res.push(encodedText[r * cols + (c + r)]);
        }
    }

    while (res.length > 0 && res[res.length - 1] === ' ') {
        res.pop();
    }

    return res.join('');
};