intnCr(intn,intr){if(n ==0|| r ==0|| n == r)return1; r =min(r, n - r);int res =1;for(int i =1; i <= r; i++) res = res *(n - i +1)/ i;return res;}vector<vector<int>>Solution::solve(intA){ vector<vector<int>> res;for(int i =0; i < A; i++){res.push_back(vector<int>(i +1));for(int j =0; j <= i; j++)res[i][j]=nCr(i, j);}return res;}