/* recursive solution */

class Solution {

public:

vector<int> getRow(int rowIndex) {

// IMPORTANT: Please reset any member data you declared, as

// the same Solution instance will be reused for each test case.

if(rowIndex == 0) return vector<int>(1, 1);

vector<int> p_row = getRow(rowIndex-1);

vector<int> c_row;

c_row.push_back(1);

for(int i = 1; i < p_row.size(); i++){

c_row.push_back(p_row[i] + p_row[i-1]);

}

c_row.push_back(1);

return c_row;

}

};

/* iterative solution */

class Solution {

public:

vector<int> getRow(int rowIndex) {

if(rowIndex < 0) return vector<int>();

vector<int> layer = {1};

vector<int> next_layer;

int k = 1;

int t;

while(k <= rowIndex){

for(int i = 0; i <= k; i++){

if(i > 0) t = layer[i-1];

else t = 0;

if(i < k) t += layer[i];

else t += 0;

next_layer.push_back(t);

}

layer = next_layer;

next_layer.clear();

k++;

}

return layer;

}

};