描述
Given a non-negative integer numRows, generate the first numRows of Pascal's triangle.
Example
Input: 5
Output:
[
[1],
[1,1],
[1,2,1],
[1,3,3,1],
[1,4,6,4,1]
]
代码
import java.util.ArrayList;
import java.util.List;
public class PascalTriangle {
public static void main(String[] args) {
System.out.println(generate(5));
}
public static List<List<Integer>> generate(int numRows) {
List<List<Integer>> result = new ArrayList<List<Integer>>(numRows);
for (int i = 0; i < numRows; i++) {
List<Integer> thisRow = new ArrayList<Integer>(i);
for (int j = 0; j <= i; j++) {
if(j==0)
thisRow.add(1);
else{
if(j<i)
thisRow.add( result.get(i - 1).get(j - 1) + result.get(i - 1).get(j));
else if(j==i)
thisRow.add(1);
}
}
result.add(thisRow);
}
return result;
}
}
