Problem
Given a non-negative index k where k ≤ 33, return the kth index row of the Pascal's triangle.
Note that the row index starts from 0.
image.png
In Pascal's triangle, each number is the sum of the two numbers directly above it.
Example
Input: 3
Output: [1,3,3,1]
Follow up:
Could you optimize your algorithm to use only O(k) extra space?
Code
static int var= [](){
std::ios::sync_with_stdio(false);
cin.tie(NULL);
return 0;
}();
class Solution {
public:
vector<int> getRow(int rowIndex) {
vector<int> res(rowIndex+1,0);
if(rowIndex>=0)
res[0] = 1;
for(int i=0;i<=rowIndex;i++){
for(int j=i;j>0;j--){
res[j] += res[j-1];
}
}
return res;
}
};
Result
119. Pascal's Triangle II.png
