卡特兰数

Posted 2021-02-10 downrainsun

https://vjudge.net/contest/284040#problem/J

#include<cstdio>
#include<cstring>
#include<algorithm>

using namespace std;

typedef long long ll;
ll mapp[40][40];
void init() {
  for(int i = 0; i < 36; i++) mapp[i][0] = 1;
    for(int i = 1;i <= 35; i++)
        for(int j = 1; j <= i; j++)
            mapp[i][j] = mapp[i - 1][j] + mapp[i][j - 1];

}
int n;
int main() {
    init();
    int ant = 0;
    while(~scanf("%d", &n)) {
        if(n == -1) break;
        printf("%d %d %lld
", ++ant, n, 2 * mapp[n][n]);
    }
    return 0;
}