Pascal’s Triangle II
Given an integer rowIndex, return the rowIndexth (0-indexed) row of the Pascal’s triangle.
In Pascal’s triangle, each number is the sum of the two numbers directly above it as shown:
Example 1:
Input: rowIndex = 3 Output: [1,3,3,1] Example 2:
Input: rowIndex = 0 Output: [1] Example 3:
Input: rowIndex = 1 Output: [1,1]
C++ Solution
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
vector<int> getRow(int rowIndex) {
vector<int> lastRow;
vector<int> row;
for (int i = 0; i < rowIndex + 1; i++) {
if (i == 0) {
row.push_back(1);
}
int curRowNum = i + 1;
int j = 0;
if (!lastRow.empty()) {
while (j < curRowNum - 1) {
int left = 0;
if (j - 1 < 0) {
left = 0;
} else {
left = lastRow[j - 1];
}
row.push_back(lastRow[j] + left);
j++;
}
row.push_back(1);
}
lastRow = row;
row.clear();
}
return lastRow;
}
