public class Solution {
public List<Integer> getRow(int rowIndex) {
List<Integer> result = new ArrayList<>(rowIndex + 1);
result.add(1);
for (int i = 1; i <= rowIndex / 2; i++) {
result.add((int)((long)result.get(i  1) * (rowIndex  i + 1) / i));
}
for (int i = rowIndex / 2 + 1; i <= rowIndex; i++) {
result.add(result.get(rowIndex  i));
}
return result;
}
}
Three points

The kth line of pascal triangle can be computed using following fomula.
[C(k, 0), C(k, 1), C(k, 2) ... C(k, k)] 
C(k, x) = C(k, x  1) * (k  x + 1) / i (Expanding C(k, x) will get you here.)

The numbers in one line is symmetric. C(k, 0) = C(k, k) C(k, 1) = C(k, k  1)