c++ solution

string encryption(string s) {
    int L = s.size();

    int rows = floor(sqrt(L));
    int cols = ceil(sqrt(L));
    if (rows * cols < L) {
        rows = cols;
    }

    vector<string> result;
    for (int c = 0; c < cols; c++) {
        string word = "";
        for (int r = 0; r < rows; r++) {
            int idx = r * cols + c;
            if (idx < L) {
                word += s[idx];
            }
        }
        result.push_back(word);
    }

    string encoded = "";
    for (int i = 0; i < result.size(); i++) {
        if (i > 0) encoded += " ";
        encoded += result[i];
    }

    return encoded;
}

def encryption(s): clean_s = s.replace(' ', '') row, col = math.floor(math.sqrt(len(clean_s))), math.ceil(math.sqrt(len(clean_s))) rst =[''] * col for i in range(len(clean_s)): rst[i%col] += clean_s[i] return ' '.join(rst )

import java.io.; import java.util.; import java.util.stream.*;

class Result {

/*
 * Complete the 'encryption' function below.
 *
 * The function is expected to return a STRING.
 * The function accepts STRING s as parameter.
 */

public static String encryption(String s) {
    // Remove spaces
    s = s.replaceAll("\\s", "");
    int len = s.length();

    // Calculate rows and columns
    int rows = (int) Math.floor(Math.sqrt(len));
    int cols = (int) Math.ceil(Math.sqrt(len));
    if (rows * cols < len) {
        rows++;
    }

    // Build the encrypted string
    StringBuilder encrypted = new StringBuilder();
    for (int c = 0; c < cols; c++) {
        for (int r = 0; r < rows; r++) {
            int index = r * cols + c;
            if (index < len) {
                encrypted.append(s.charAt(index));
            }
        }
        encrypted.append(" ");
    }

    return encrypted.toString().trim();
}

}

public class Solution { public static void main(String[] args) throws IOException { BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in)); BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

    String s = bufferedReader.readLine();

    String result = Result.encryption(s);

    bufferedWriter.write(result);
    bufferedWriter.newLine();

    bufferedReader.close();
    bufferedWriter.close();
}

}