问题描述: 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? 问题分析: 第 rowIndex 行有 rowIndex + 1 个元素,给这 rowIndex + 1个元素赋初值 0, row的第一个…
题目: 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? 题解: 为了达到O(k)的空间复杂度要求,那么就要从右向左生成结果.相当于你提前把上一行的计算出来,当前行就可以用上一次计算出的结果计算了…
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? 这道题倒是不难,有个有意思的地方是可以优化到O(k)的空间复杂度.下面先上O(k^2)的算法. @Test public List<Integer>…
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? Subscribe to see which companies asked this question 依次在上一行的基础上计算下一行,技巧就是从后…
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>();…
Given numRows, generate the first numRows of Pascal's triangle. For example, given numRows = 5, Return [ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1] ] 解题思路: 观察法,JAVA实现如下: public List<List<Integer>> generate(int numRows) { List<List<Int…
Pascal's Triangle: Given numRows, generate the first numRows of Pascal's triangle. For example, given numRows = 5,Return [ [1], [1,1], [1,2,1], [1,3,3,1], [1,4,6,4,1] ] 已知行数生成帕斯卡三角.实际上只要有第i层,那么就能生成第i+1层.每次新生成的层加入最终集合中即可. public List<List<Integer>…
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? 上一道题的延伸版,就是直接求出第k行的数,要求用o(k)的空间复杂度. 也是直接相加就可以了. public class Solution { pub…