naivA(n)
1. if n ≤ 1 then return 1;
2. sum = 0;
3. for i = 1 to n
4.
sum += naivA(i i 1) · naivA(n \ i);
5. return sum;
naivA(n)
1. if n ≤ 1 then return 1;
2. sum = 0;
3. for i = 1 to n
4. sum += naivA(i -1) · naivA(n - i);
5. return sum;
实现的公式如下:
A(n)=1 ,n=0
A(n)=1 ,n=1
A(n)= Σ A(i-1)*A(n-i) ,n>=2
不好意思多粘了一段伪代码，一样的内容，大家忽略就好，只看其一。
public static void main(String[] args) throws Exception {
System.out.println(goSum(3));
}
private static int goSum(int n){
int sum = 0;
if(n==0){
sum = 1;
}
if (n==1){
sum = 1;
}else {
for (int i = 1; i <= n; i++) {
sum += goSum(i-1)*goSum(n-i);
}
}
return sum;
}