1 #include<cstdio> 2 #include<cmath> 3 #include<iostream> 4 #include<algorithm> 5 #include<cstring> 6 #include<vector> 7 #include<string> 8 using namespace std; 9 10 11 vector<string> ans[20][15];12 string a[15];13 int n;14 void dfs(int l, int r)15 {16     string s;17     if (ans[l][r].size())18         return;19     if (l == r)20         ans[l][r].push_back(a[l]);21     else22     {23         for (int i = l; i < r; i++)24         {25             dfs(l, i);26             dfs(i + 1, r);27             int m1 = ans[l][i].size(), m2 = ans[i+1][r].size();28             for (int j = 0; j < m1; j++)29             {30                 for (int k = 0; k < m2; k++)31                 {32                     if (l == i && i + 1 == r)33                         s = "(" + ans[l][i][j] + "*" + ans[i + 1][r][k] + ")";34                     else35                     {36                         s = "(" + ans[l][i][j] + ans[i+1][r][k] + ")";37                     }38                     ans[l][r].push_back(s);39                 }40             }41         }42     }43 }44 int main()45 {46     cin >> n;47     for (int i = 1; i <= n; i++)48         cin >> a[i];49     dfs(1, n);50     int m = ans[1][n].size();51     for (int i = 0; i < m; i++)52         cout << ans[1][n][i] << endl;53     return 0;54 }