Leetcode 119 Pascal's Triangle II 数论递推

杨辉三角，这次要输出第rowIndex行

用滚动数组t进行递推

t[(i+1)%2][j] = t[i%2][j] + t[i%2][j - 1];

 class Solution {
 public:
     vector<int> getRow(int rowIndex) {
         if(rowIndex < ) return vector<int>(rowIndex + ,);
         int n = rowIndex;
         vector<int> t[];
         for(int i = ; i < ; ++i){
            t[i].resize(n + , );
         }
         for(int i = ; i <= n; ++i){
             for(int j = ; j < i; ++j){
                 t[(i+)%][j] = t[i%][j] + t[i%][j - ];
             }
         }
         return t[(n+) % ];
     }
 };