首页 > 代码库 > Problem Pascal's Triangle II
Problem Pascal's Triangle II
Problem Description:
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?
Solution:
1 public List<Integer> getRow(int rowIndex) { 2 List<Integer> row = new ArrayList<Integer>(); 3 List<Integer> preRow = new ArrayList<Integer>(); 4 for (int i = 0; i <= rowIndex; i++) { 5 preRow.add(1); 6 row.add(1); 7 } 8 for (int i = 0; i <= rowIndex; i++) { 9 for (int j = 0; j <= i; j++) {10 if (j == 0 || j == i) {11 row.set(j, 1);12 } else {13 row.set(j, preRow.get(j-1)+preRow.get(j));14 }15 }16 List<Integer> temp = preRow;17 preRow = row;18 row = temp;19 }20 21 return preRow;22 }
声明：以上内容来自用户投稿及互联网公开渠道收集整理发布，本网站不拥有所有权，未作人工编辑处理，也不承担相关法律责任，若内容有误或涉及侵权可进行投诉： 投诉/举报 工作人员会在5个工作日内联系你，一经查实，本站将立刻删除涉嫌侵权内容。