LeetCode 119: Pascal's Triangle II

循环使用上一行相邻数值相加，需要一个中间变量储存。也可以使用公式，

class Solution {
public:
    vector<int> getRow(int rowIndex) {
        vector<int> row;
	    row.push_back(1);
	    for (int i = 1; i <= rowIndex; ++i)
	    {
		    int t = 1, temp;
		    for (int j = 1; j<i; ++j)
		    {
			    temp = t;
			    t = row[j];
			    row[j] = temp + row[j];
		    }
		    row.push_back(1);
	    }
	    return row;
    }
};