棋盘的一角走到另一角并且不越过对角线，卡特兰数，数据量小，可以当做dp求路径数
1 #include<stdio.h>
2 long long a[36][36];
3 int main()
4 {
5 int n,count=0;
6 while (scanf("%d",&n)!=EOF&&n!=-1)
7 {
8 int i,j;
9 long long s;
10 count++;
11 for (i=1;i<=n;i++) a[0][i]=1;
12 for (i=1;i<n;i++)
13 {
14 a[i][i]=a[i-1][i];
15 for (j=i+1;j<=n;j++) a[i][j]=a[i][j-1]+a[i-1][j];
16 }
17 s=a[n-1][n]*2;
18 printf("%d %d %I64d
",count,n,s);
19 }
20 return 0;
21 }