$C_{n+1}= \sum_{k=0}^{n}C_{k}C_{n-k}$
#define M 35
ll C[M+1];
void catalan()
{
C[0]=C[1]=1;
for(int i=2; i<=M; i++)
{
C[i]=0;
for(int j=0; j<i; j++)
C[i] += C[j]*C[i-j-1];
}
}
$C_{n+1}= \sum_{k=0}^{n}C_{k}C_{n-k}$
#define M 35
ll C[M+1];
void catalan()
{
C[0]=C[1]=1;
for(int i=2; i<=M; i++)
{
C[i]=0;
for(int j=0; j<i; j++)
C[i] += C[j]*C[i-j-1];
}
}
