题解（点个赞吧）

#include<bits/stdc++.h>
using namespace std;
int main(){
    cout << "                                1" << endl;
    cout << "                             1     1" << endl;
    cout << "                          1     2     1" << endl;
    cout << "                       1     3     3     1" << endl;
    cout << "                    1     4     6     4     1" << endl;
    cout << "                 1     5    10    10     5     1" << endl;
    cout << "              1     6    15    20    15     6     1" << endl;
    cout << "           1     7    21    35    35    21     7     1" << endl;
    cout << "        1     8    28    56    70    56    28     8     1" << endl;
    cout << "     1     9    36    84   126   126    84    36     9     1" << endl;
}