Pascal's Triangle II

Given an index k, return the k^th 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?

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[     [1],    [1,1],   [1,2,1],  [1,3,3,1], [1,4,6,4,1]]

帕斯卡三角

根据上面找规则

比如rowindex=5,则应该输出[1,5,10,10,5,1]

规则为 rowList[i] = (int)((long)rowList[i-1]*(rowIndex-(i-1))/(i));代码如下：
public class GetRow {    public static void main(String[] args) {        int rowIndex=3;        GetRow gr=new GetRow();        System.out.println(gr.getRow(rowIndex));    }    public List<Integer> getRow(int rowIndex) {        Integer[] rowList = new Integer[rowIndex+1];        rowList[0] = 1;        for(int i=1; i<rowList.length;i++) {            rowList[i] = (int)((long)rowList[i-1]*(rowIndex-(i-1))/(i));        }        return Arrays.asList(rowList);    }}