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]
]
class Solution {
public List<List<Integer>> generate(int numRows) {
List<List<Integer>> triangle = new ArrayList<List<Integer>>();
if (numRows <=0){
return triangle;
}
for (int i=0; i<numRows; i++){
List<Integer> row = new ArrayList<Integer>();
for (int j=0; j<i+1; j++){
if (j==0 || j==i){
row.add(1);
} else {
row.add(triangle.get(i-1).get(j-1)+triangle.get(i-1).get(j));
}
}
triangle.add(row);
}
return triangle;
}
}
原文：http://www.cnblogs.com/GodBug/p/7425619.html