解析
思路和上一题杨辉三角一致
代码
class Solution {
public:vector<vector<int>> generate(int numRows) {if(numRows == 1){vector<vector<int>> ddRoot;vector<int> root;root.push_back(1);ddRoot.push_back(root);return ddRoot;}else{vector<vector<int>> ddRoot = generate(numRows-1);vector<int> root;int length = ddRoot.size()-1;root.push_back(1);for(int i = 1; i < ddRoot[length].size();i++){root.push_back(ddRoot[length][i-1] + ddRoot[length][i]);}root.push_back(1);ddRoot.push_back(root);return ddRoot;}}
};