My Leetcode: Spiral Matrix II ( Java + Python)

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

For example,
Given n = 3,

You should return the following matrix:

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

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

	For example,
	Given n = 3,

	You should return the following matrix:
	[
	[ 1, 2, 3 ],
	[ 8, 9, 4 ],
	[ 7, 6, 5 ]
	]
	"""
	class Solution:
	# @return a list of lists of integer
	def generateMatrix(self, n):
	if n<=0:
	return []

	# row[:] mean shallow copy each row in [[0]n]n
	# we cannot not use row replace row[:] here
	matrix=[row[:] for row in [[0]n]n]

	row_st=0
	row_ed=n-1

	col_st=0
	col_ed=n-1
	current=1

	while (True):
	if current>n*n:
	break
	for c in range (col_st, col_ed+1):
	matrix[row_st][c]=current
	current+=1
	row_st+=1
	for r in range (row_st, row_ed+1):
	matrix[r][col_ed]=current
	current+=1
	col_ed-=1
	for c in range (col_ed, col_st-1, -1):
	matrix[row_ed][c]=current
	current+=1
	row_ed-=1
	for r in range (row_ed, row_st-1, -1):
	matrix[r][col_st]=current
	current+=1
	col_st+=1
	return matrix

view raw SpiralMatrixII.py hosted with ❤ by GitHub

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

	For example,
	Given n = 3,

	You should return the following matrix:
	[
	[ 1, 2, 3 ],
	[ 8, 9, 4 ],
	[ 7, 6, 5 ]
	]

	public class Solution {
	public int[][] generateMatrix(int n) {
	// Start typing your Java solution below
	// DO NOT write main() function
	if (n<=0){
	return new int[0][0];
	}
	int [][] matrix=new int[n][n];

	int beginX=0;
	int endX=n-1;

	int beginY=0;
	int endY=n-1;
	int current=1;

	while (current<=n*n){
	for (int col=beginX; col<=endX; col++){

	matrix[beginY][col]=current++;
	}
	beginY++;
	for (int row=beginY; row<=endY; row++){
	matrix[row][endX]=current++;
	}
	endX--;

	for (int col=endX; col>=beginX; col--){
	matrix[endY][col]=current++;
	}
	endY--;

	for (int row=endY; row>=beginY; row--){
	matrix[row][beginX]=current++;
	}
	beginX++;
	}

	return matrix;
	}
	}

My Leetcode