http://oj.leetcode.com/problems/pascals-triangle-ii/ 杨辉三角2,比杨辉三角要求的空间上限制Could you optimize your algorithm to use only O(k) extra space?其实计算当前行,也只用到前一行了.再前面的没有用. class Solution { public: vector<int> getRow(int rowIndex) { // IMPORTANT: Please reset a…

http://oj.leetcode.com/problems/pascals-triangle/ 杨辉三角 先分析数据,找出规律 ans[row][col] = ans[row-1][col-1]+ans[row-1][col] #include <iostream> #include <vector> #include <string> using namespace std; class Solution { public: vector<vector<…

Problem: 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] ] Summary: 输出杨辉三角的前n行. Solution: 方法类似于LeetCode 119 Pascal's Triangle II class Solution { publ…

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? 118. Pascal's Triangle 的拓展,给一个索引k,返回杨辉三角的第k行. 解法:题目要求优化到 O(k) 的空间复杂,那么就不能把每…

[LeetCode]Pascal's Triangle II 解题报告 标签(空格分隔): LeetCode 题目地址:https://leetcode.com/problems/pascals-triangle-ii/description/ 题目描述: 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 yo…

Given a non-negative index k where k ≤ 33, return the kth index row of the Pascal's triangle. Note that the row index starts from 0. In Pascal's triangle, each number is the sum of the two numbers directly above it. Example: Input: 3 Output: [1,3,3,1…

Problem: 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? Summary: 返回杨辉三角(帕斯卡三角)的第k行. Solution: 1. 若以二维数组的形式表示杨辉三角,则可轻易推算出ro…

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 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] ]分析:此题其实就是表现出帕斯卡三角的特征:它是一个三角形矩阵,其顶端是 1,视为(row0).第1行(row1)(1&1)两个1,这两个1是由他们上头左右两数之和 (不在三角形内的数视为0).依此类推产…

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? 题目标签:Array 这道题目与之前那题不同的地方在于,之前是给我们一个行数n,让我们把这几行的全部写出来,这样就可以在每写新的一行的时候根据之前的那…