48. Rotate Image

Posted 2022-10-08 johnnyzhao

/**
48. Rotate Image
https://leetcode.com/problems/rotate-image/description/
*/
class Solution 
    public void rotate(int[][] matrix) 
        //N x N matrix have floor(N/2) square cycers, for example 4x4 matrix have 2 cycles
        if (matrix==null || matrix[0].length==0)
            return;
        
        int n = matrix.length;
        for (int x = 0;x<n/2;x++)
            for (int y = x;y<n-x-1;y++)
                int temp = matrix[x][y];
                //move value from right to top
                matrix[x][y] = matrix[n-1-y][x];
                // move values from bottom to right 
                 matrix[n-1-y][x]= matrix[n-1-x][n-1-y];
                  // move values from left to bottom 
                matrix[n-1-x][n-1-y] = matrix[y][n-1-x];
                //assign temp to left
                matrix[y][n-1-x] = temp;
            
        
    


//kotlin

class Solution 
    fun rotate(matrix: Array<IntArray>): Unit 
        if (matrix.isEmpty() || matrix[0].isEmpty())
            return
        val n = matrix.size
        for (i in 0..(n / 2 - 1)) 
            for (j in i..n - 2 - i) 
                val temp = matrix[i][j]
                println("temp:" + temp)
                println("matrix[n-1-j][i]:" + matrix[n - 1 - j][i])
                matrix[i][j] = matrix[n - 1 - j][i]
                matrix[n - 1 - j][i] = matrix[n - 1 - i][n - 1 - j]
                matrix[n - 1 - i][n - 1 - j] = matrix[j][n - 1 - i]
                matrix[j][n - 1 - i] = temp