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/**

* Practiced on 12/16/2012

*

* Given an index k, return the kth row of the Pascal's triangle.

*

* For example, given k = 3,

* Return [1,3,3,1].

*

* Note:

* Could you optimize your algorithm to use only O(k) extra space?

*/

package com.congli.leetcode;

import java.util.ArrayList;

public class PascalsTriangleII {

public ArrayList<Integer> getRow(int numRows)

{

ArrayList<Integer> result = new ArrayList<Integer>();

if(numRows < 0) return result;

result.add(1);

if(numRows == 0) return result;

for(int row = 1; row <= numRows; ++row)

{

ArrayList<Integer> rowArray = new ArrayList<Integer>();

rowArray.add(1);

for(int j = 1; j < row; ++j)

{

rowArray.add(result.get(j-1) + result.get(j));

}

rowArray.add(1);

result = rowArray;

}

return result;

}

}