Making it two-dimensional (with.Java)

This is an article about the problem of “making it 2-dimensional.”

As I solve coding test problems, I look back on the problems I solved and look into different solution methods to learn more.

Let’s look at the problem first.

problem

The integer array num_list and the integer n are given as parameters.

Complete the solution function to return num_list by converting it to a two-dimensional array as described below.

Since num_list is [1, 2, 3, 4, 5, 6, 7, 8] with length 8 and n is 2, we change num_list to 2*4 array as follows:

When changing to 2-dimensional, the elements of num_list are divided into n elements from the beginning and changed to a 2-dimensional array.

Restrictions

• The length of num_list is several times n.
• 0 ≤ length of num_list ≤ 150
• 2 ≤ n < length of num_list

Input/Output Example

My solution to the problem

class Solution {
     public int[][] solution(int[] num_list, int n) {
         int[][] answer = new int[num_list.length / n][n];
         int temp = 0;
         for(int i = 0; i < num_list.length / n; i++){
             for(int j = 0; j < n; j++){
                 answer[i][j] = num_list[temp++];
             }
         }
         return answer;
     }
}

Solution explanation

Main Logic

answer defines the size of the array as num_list.length / n rows and n columns.

Move the elements of a one-dimensional array into a two-dimensional array using a double loop.

Function Description

We used a method of initializing the array and assigning values directly without using a special function.

Direction for improvement

Depending on the input or situation, it may be a good idea to add an option to choose how to fill or ignore the last row.

Through exception handling, the code can be supplemented to ensure appropriate processing by checking the size of num_list and the condition of n.