杨辉三角（金字塔型）

#includeint main(){int a[20][50];int n;scanf("%d", &n);for (int i = 1; i <= n; i++){a[i][1] = 1;//首尾置为1a[i][i] = 1;}for (int i =3; i <= n; i++){for (int j =2; j

6 1 1 1 1 2 1 1 3 3 1 1 4 6 4 1 1 5 10 10 5 1