[leetcode]Pascal's Triangle

问题描述：

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]
]

import java.util.ArrayList;
import java.util.List;


public class Pascals_Triangle {

	public List
  
   > generate(int numRows) {
        if(numRows <=0)
        	return new ArrayList();
        
        List
   
    > result = new ArrayList
    
     >(); for(int i=0; i
     
       list = new ArrayList
      
       (); if(result.size() == 0){ list.add(1); result.add(list); } else{ list.add(1); List
       
         tmplist = result.get(result.size()-1); for(int j = 0; j