/* Author: Andy, [email protected] Date: Apr 16, 2013 Problem: Pascal's Triangle Difficulty: Easy Source: http://leetcode.com/onlinejudge#question_118 Notes: 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] ] Solution: ..... */ public class Solution { public List> generate(int numRows) { List> res = new ArrayList>(); if (numRows < 1) return res; List temp = new ArrayList(); temp.add(1); res.add(temp); for (int i = 1; i < numRows; ++i) { List t = new ArrayList(); t.add(1); for (int j = 1; j < i; ++j) { t.add(res.get(i-1).get(j-1) + res.get(i-1).get(j)); } t.add(1); res.add(t); } return res; } }