[릿코드, Leetcode] [JAVA] Rotate Image

Rotate Image - LeetCode

Leetcode - Rotate Image

설명

You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise).

You have to rotate the image in-place, which means you have to modify the input 2D matrix directly. DO NOT allocate another 2D matrix and do the rotation.

Example:

Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]

Output: [[7,4,1],[8,5,2],[9,6,3]]

제한사항

• matrix.length == n
• matrix[i].length == n
• 1 <= n <= 20
• -1000 <= matrix[i][j] <= 1000

 

 

소스코드

class Solution {
    public void rotate(int[][] matrix) {
        int[][] map = new int[matrix.length][matrix.length];

        for (int i=0; i<matrix.length; i++) {
            for (int j=0; j<matrix.length; j++) {
                map[i][j] = matrix[matrix.length - 1 - j][i];
            }
        }
        
        for (int i=0; i<matrix.length; i++) {
            for (int j=0; j<matrix.length; j++) {
                matrix[j][i] = map[j][i];
            }
        }
    }
}

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