Sprial Matrix || problem leetcode

 Given a positive integer n, generate an n x n matrix filled with elements from 1 to n2 in spiral order.


 


Example 1:



Input: n = 3

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

Example 2:


Input: n = 1

Output: [[1]]

 


Constraints:


1 <= n <= 20


class Solution {
    public int[][] generateMatrix(int n) {
        int[][] matrix = new int[n][n];
        int top = 0, bottom = n - 1, left = 0, right = n - 1;
        int num = 1; // Start filling from 1 to n^2

        while (num <= n * n) {
            // Move right
            for (int i = left; i <= right; i++) {
                matrix[top][i] = num++;
            }
            top++;

            // Move down
            for (int i = top; i <= bottom; i++) {
                matrix[i][right] = num++;
            }
            right--;

            // Move left
            if (top <= bottom) {
                for (int i = right; i >= left; i--) {
                    matrix[bottom][i] = num++;
                }
                bottom--;
            }

            // Move up
            if (left <= right) {
                for (int i = bottom; i >= top; i--) {
                    matrix[i][left] = num++;
                }
                left++;
            }
        }

        return matrix;
    }

    public static void main(String[] args) {
        Solution sol = new Solution();
        int n = 3; // Example input
        int[][] result = sol.generateMatrix(n);

        // Print the matrix
        for (int[] row : result) {
            for (int num : row) {
                System.out.print(num + " ");
            }
            System.out.println();
        }
    }
}



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