[Leetcode] Pascal's Triangle II (Java)

Given an index k, return the kth row of the Pascal's triangle.

For example, given k = 3,

Return

[1,3,3,1]

.

更新一个数组，并保存每行的前一个元素即可

public class Solution {
public ArrayList<Integer> getRow(int rowIndex) {

ArrayList<Integer> ret = new ArrayList<Integer>();
int[] num = new int[rowIndex+1];

for(int i=0;i<=rowIndex;i++){
num[i]=1;
}

for(int i=0;i<=rowIndex;i++){
int tmp = 1;
int cur = 1;
for(int j=1;j<i;j++){
cur = num[j];
num[j]=tmp+num[j];
tmp = cur;
}
}

for(int i=0;i<=rowIndex;i++){
ret.add(num[i]);
}

return ret;
}
}