Java for LeetCode 119 Pascal's Triangle II

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

For example, given k = 3,
Return [1,3,3,1].

解题思路:

注意,本题的k相当于上题的k+1,其他照搬即可,JAVA实现如下:

    public List<Integer> getRow(int rowIndex) {
        List<Integer> alist=new ArrayList<Integer>();
        rowIndex++;
    	if(rowIndex<=0)
			return alist;
    	alist.add(1);
    	for(int i=2;i<=rowIndex;i++){
			List<Integer> alist2=new ArrayList<Integer>();
			alist2.add(1);
			for(int j=1;j<i-1;j++){
				alist2.add(alist.get(j-1)+alist.get(j));
			}
			alist2.add(1);
			alist=alist2;
		}
    	return alist;
    }

 

posted @ 2015-05-24 16:55  TonyLuis  阅读(213)  评论(0编辑  收藏  举报