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:
没啥好说的，注意某行的长度 = 该行index + 1.
public class Solution
{
public List<List<Integer>> generate(int numRows)
{
if(numRows == 0)
return new ArrayList<>();
List<List<Integer>> result = new ArrayList<>();
List<Integer> firstList = new ArrayList<>();
firstList.add(1);
result.add(firstList);
for(int i = 1; i < numRows; i++)
{
List<Integer> preList = result.get(i - 1);
List<Integer> curList = new ArrayList<Integer>();
curList.add(1);
for(int j = 1; j < i; j ++)
{
curList.add(preList.get(j - 1) + preList.get(j));
}
curList.add(1);
result.add(curList);
}
return result;
}
}
