Spiral Matrix (Java)

LeetCode

Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.

For example,
Given the following matrix:

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

You should return [1,2,3,6,9,8,7,4,5].

	Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.
	For example,
	Given the following matrix:
	[
	[ 1, 2, 3 ],
	[ 4, 5, 6 ],
	[ 7, 8, 9 ]
	]
	You should return [1,2,3,6,9,8,7,4,5].
	public class SpiralMatrix {
	public ArrayList<Integer> spiralOrder(int[][] matrix) {
	// Start typing your Java solution below
	// DO NOT write main() function
	ArrayList<Integer> result=new ArrayList<Integer> ();
	if (matrix==null|| matrix.length==0){
	return result;
	}
	int beginX=0;
	int endX=matrix[0].length-1;
	int beginY=0;
	int endY=matrix.length-1;
	while(true){
	for (int col=beginX; col<=endX; col++){
	result.add(matrix[beginY][col]);
	}
	if (++beginY>endY){
	break;
	}
	for (int row=beginY; row<=endY; row++){
	result.add(matrix[row][endX]);
	}
	if (--endX<beginX){
	break;
	}
	for (int col=endX; col>=beginX; col--){
	result.add(matrix[endY][col]);
	}
	if (--endY<beginY){
	break;
	}
	for (int row=endY; row>=beginY; row--){
	result.add(matrix[row][beginX]);
	}
	if (++beginX>endX){
	break;
	}
	}
	return result;
	}
	}

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