Pascal's Triangle - LeetCode

Given numRows, generate the first numRows of Pascal's triangle.

For example, given numRows = 5,
Return

[     [1],    [1,1],   [1,2,1],  [1,3,3,1], [1,4,6,4,1]]

class Solution {public:    vector<vector<int> > generate(int numRows) {        vector<vector<int>> Triangle;    vector<int> result;        if (numRows == 0)        {    return Triangle;    }    result.push_back(1);    Triangle.push_back(result);    int temp;    int k;//下标    int r;    for (r = 1; r <= numRows - 1; r++)    {     result.clear();    int rfirst = (r + 1) * r / 2;    int rlast = rfirst + r;    for(k = rfirst; k <= rlast; k++)    {    if (k == rfirst || k == rlast)    {    temp = 1;    }    else    {    temp = Triangle[r - 1][k - rfirst - 1] + Triangle[r - 1][k - rfirst];    }    result.push_back(temp);    }    Triangle.push_back(result);       }    return Triangle;    }};